Re[3]: *ist D sensor and 35mm lens resolution
Please ignore my previous message that was originated by my mail program! I am playing catch-up on over 7,000 odd messages and my mail reader program must have had a fit! Harryo
Re[2]: *ist D sensor and 35mm lens resolution
Hello Rob, Wednesday, March 10, 2004, 1:34:44 AM, you wrote: RS> On 9 Mar 2004 at 18:24, J. C. O'Connell wrote: >> Oh no, very mistaken! Yes of course a 14mp FF sensor will be better than >> a 6Mp FF sensor in terms of resolution, but a 6MP FF sensor is DEFINATELY better >> than a 6MP APS sensor, not only will the image be sharper due to lens >> limitations, >> the FF image will be less noiser due to larger pixel area. The only >> downside >> to FF vs. APS for a given Mp is cost. RS> John, you're not listening, many of us are very happy with the noise RS> performance and latitude afforded by our puny APS sized 6MP sensors, many of us RS> however would like full frame coverage. The cost is mainly a function of the RS> substrate size not the density, CCD sensors of any density have huge structures RS> compared with most any other type of VLSI semiconductor in production. In other RS> words the cost to produce a 6MP or 14MP FF sensor is going to be similar. RS> Rob Studdert RS> HURSTVILLE AUSTRALIA RS> Tel +61-2-9554-4110 RS> UTC(GMT) +10 Hours RS> [EMAIL PROTECTED] RS> http://members.ozemail.com.au/~distudio/publications/ RS> Pentax user since 1986, PDMLer since 1998 -- Best regards, Haroldmailto:[EMAIL PROTECTED]
RE: *ist D sensor and 35mm lens resolution
Erm, excuse me, but did somebody say my name...? How the heck did I get in here?!?! lol! Well, here goes... I haven't been following this thread, and it is ironic really as the reason is exactly what you are all discussing. It was simply above my "need" for technical learning... In fact, I was merrily plodding along pressing "delete" everytime I saw this subject line until somebody gave me a heads up that I was "being talked about" lol... Rob is correct (we talk on the phone all the time), that I am very interested in the technical stuff, but with conditions. I am not into techno speak, just for entertainment purposes and in fact, usually avoid it at all costs cause it bores me to tears (that's just the girl comin' out in me!) unless it is completely relevant. BUT, obviously there are times when I HAVE to join in cause I couldn't possibly become a better photographer with out it. For eg, I pretty much tuned out on the wide lens discussions, and the whole "aperture ring missing" thingy for the DA lenses, UNTIL I got my *istD and both topics became not only relevant to me, but an essential part of what I needed to know to get the shots that I wanted. Likewise with the Neat Image/noise reduction discussion, until I took some shots where the noise in the sky annoyed the crap outta me, so I thought "hey, I'd better take notice of what these guys are on about..." Likewise, if for some reason, one day I realise that I can't capture a certain image without knowing the difference between and APS and FF sensor, than most likely my ears will "prick up" when next it is discussed (and i'm sure it will be discussed again and again! lol). I really couldn't give a toss about the difference between Apples and PCs, but if I discovered that a PC couldn't do what I needed/wanted to but an Apple would, then I might start to "listen in" to those discussions a bit more... Jens said it perfectly actually... "The beauty of a mailing list is, that everybody can write about what's important to them and could be helpfull to others. And everybody can read what ever seem intersting." or whatever they need to learn at any given time. The thing is, I have so many things going on in my life and in my mind at any given time, that I really just don't have the time or the capacity to sit and ponder how many elements a certain lens has, or how many millimetres difference one sensor is from another. HOWEVER, if I discover that by a certain lens having a special number of elements will create a certain effect that I want to attempt or more importantly, that it will prevent certain things from showing up that I don't like, than I make a point to learn all I can about it. I prefer to learn the rudiments of things and delve deeper if it seems to be useful to know. I don't really care too much for the "why things work how they do" but more for the "what things can do" or "what results things can produce". Thus the reason, a while back, that I had no idea that my flash that only zoomed to 80mm was usable with a 135mm lens, cause I had never had the need to use it that way. Then, I found a need, learned as much as I can and now use it all the time... I view this list more as a learning TOOL than as a learning "school" (as well as hilarious entertainment at times!). ie. I can CHOOSE to learn what I NEED to learn rather than having to sit through every "class" and listen to information that isn't relevant to me. It's the same approach that I take with OT stuff. If you guys wanna talk about whisky and fast cars, than go for it. It doesn't affect me in the least, I simply delete what I don't need to take in. Of course, the same goes for advice given - I prefer to only comment when I feel that I can offer advice that is from a different perspective than what others can/have/will offer, and never comment if I don't think that what I have to say would be helpful to the person requesting the advice or if I feel that a person knows more than me anyways (which is usually the case, hence me not handing out advice very often!). Ok, going back into my black hole of technical oblivion now... the fairymeister. -Original Message- From: Lon Williamson [mailto:[EMAIL PROTECTED] Sent: Thursday, 11 March 2004 9:01 AM To: [EMAIL PROTECTED] Subject: Re: *ist D sensor and 35mm lens resolution And she takes good shots without knowing what she wants to know. I think we probably agree more than not, Rob. Rob Studdert wrote: > Strangely Tan seems quite interested in the technicalities, at least that's the > impression I got during our conversations, am I right Tan?
RE: *ist D sensor and 35mm lens resolution
not only that, but use the best film and digital settings, i.e. ISO 50 not ISO200. jco J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Mark Erickson [mailto:[EMAIL PROTECTED] Sent: Wednesday, March 10, 2004 6:24 PM To: pentax-discuss Subject: RE: *ist D sensor and 35mm lens resolution Jens, Interesting result. As you mentioned in your text, your scanner may be the limiting factor for your MZ-S => Fuji Superia => Epson 3200 flow. The imaging system in the scanner probably isn't sharp enough to capture all of the detail in the film. I have an Epson 2450 (the older version of the 3200). A few months ago, I shot some resolution targets with a medium format film camera and scanned them with my 2450. I saw a lot more detail in the film with a 30x microscope than was visible in the scanned results. It would be interesting to take your film and have it commercially scanned with a high-end scanner to see how much better (if at all) the results are compared to your 3200. --Mark >Hi all >I have now posted my Analog versus Digital test shots. I know that this >thread is not about this. But I was hoping to maybe inspire some of you guys >to make similar tests, using the *ist D and an analog Pentax camera, maybe >even using the same lenses, or lenses of comparable quality and resolution. > >Please visit: http://gallery50012.fotopic.net/c132825.html >You may consider this a PAW. > >All the best >Jens Bladt
RE: *ist D sensor and 35mm lens resolution
Jens, Interesting result. As you mentioned in your text, your scanner may be the limiting factor for your MZ-S => Fuji Superia => Epson 3200 flow. The imaging system in the scanner probably isn't sharp enough to capture all of the detail in the film. I have an Epson 2450 (the older version of the 3200). A few months ago, I shot some resolution targets with a medium format film camera and scanned them with my 2450. I saw a lot more detail in the film with a 30x microscope than was visible in the scanned results. It would be interesting to take your film and have it commercially scanned with a high-end scanner to see how much better (if at all) the results are compared to your 3200. --Mark Hi all I have now posted my Analog versus Digital test shots. I know that this thread is not about this. But I was hoping to maybe inspire some of you guys to make similar tests, using the *ist D and an analog Pentax camera, maybe even using the same lenses, or lenses of comparable quality and resolution. Please visit: http://gallery50012.fotopic.net/c132825.html You may consider this a PAW. All the best Jens Bladt
Re: *ist D sensor and 35mm lens resolution
And she takes good shots without knowing what she wants to know. I think we probably agree more than not, Rob. Rob Studdert wrote: Strangely Tan seems quite interested in the technicalities, at least that's the impression I got during our conversations, am I right Tan?
Re: *ist D sensor and 35mm lens resolution
And that is perfectly all right. There are some that are more interested in having one of everything Pentax ever made, that is all right too. If I had the money I would probably own hundreds of cameras, but I would not take a lot more photos than I would now if I had the money. And again that is all right. Some of us just take snapshots, and that is all right. Some of us are into pretty pictures, and that is all right. Some are into street photography, and that is all right. Some of us only take photos if someone pays us, and that is all right. Some of us never take photos, but just have to have the newest, latest digital SLR, and that is all right. In fact about the only thing I find not all right on this list is the insufferable attitude that what I, or they, do is better than what someone else chooses to do. -- Bill Owens wrote: My comment was meant to say that there are some people here who are more concerned with technical issues than they are with taking pictures. -- graywolf http://graywolfphoto.com "You might as well accept people as they are, you are not going to be able to change them anyway."
RE: *ist D sensor and 35mm lens resolution
FF 35mm is more than 50% wider angle of coverage compared to *istD sensor, that is HUGE for a given focal length but not anywhere near the difference a tiny P&S sensor would be. that would be mega-HUGE. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Rob Studdert [mailto:[EMAIL PROTECTED] Sent: Wednesday, March 10, 2004 5:10 PM To: [EMAIL PROTECTED] Subject: Re: *ist D sensor and 35mm lens resolution On 10 Mar 2004 at 8:58, Gonz wrote: > Not proven, but there is some empirical evidence. Some of those P&S > digitals have very tiny sensors, but lenses to match the proper image > circle. If you calculate the resolution of those lenses, then they come > out quite high. Getting back to DA lenses we know the size of the *ist D sensor and it's not that much smaller than 35mm FF. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
Re: *ist D sensor and 35mm lens resolution
On 10 Mar 2004 at 8:58, Gonz wrote: > Not proven, but there is some empirical evidence. Some of those P&S > digitals have very tiny sensors, but lenses to match the proper image > circle. If you calculate the resolution of those lenses, then they come > out quite high. Getting back to DA lenses we know the size of the *ist D sensor and it's not that much smaller than 35mm FF. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
Re: *ist D sensor and 35mm lens resolution
It's quite hard to go out and take photos on a mailing list. Personally I'd choose to take photos in the real world and discuss technical issues online. :-) S Bill Owens wrote: Oh yes, the technical issues are much more important that actually going out and taking photos.
Re: *istD sensor and 35mm lens resolution
On Wed, 10 Mar 2004 [EMAIL PROTECTED] wrote: > > From: "J. C. O'Connell" <[EMAIL PROTECTED]> > > could be because they are stuck with the 45.5mm flange > > registration and they are designing even shorter focal length > > zoom lenses, the retrofocus factor is kicking their ass. > > > > The only way they will ever get maximum performance from > > a APS sensor system is lenses and bodies designed from the beginning > > for APS sensors, i.e. the new Olympus DSLR system. > > Or change the mirror to allow for the lens optics to protrude > back beyond the actual mount, as Canon as done with one lens > and one camera. A full-frame sensor would be a better answer. How much does that really help? I think it would allow them to make the rear optic about 5mm closer (about half of the height difference between the CCD size and 35mm film size). I don't know enough about lens design to know how helpful that is. alex
Re: *istD sensor and 35mm lens resolution
> From: "J. C. O'Connell" <[EMAIL PROTECTED]> > could be because they are stuck with the 45.5mm flange > registration and they are designing even shorter focal length > zoom lenses, the retrofocus factor is kicking their ass. > > The only way they will ever get maximum performance from > a APS sensor system is lenses and bodies designed from the beginning > for APS sensors, i.e. the new Olympus DSLR system. Or change the mirror to allow for the lens optics to protrude back beyond the actual mount, as Canon as done with one lens and one camera. A full-frame sensor would be a better answer. DJE
Re: *ist D sensor and 35mm lens resolution
My comment was meant to say that there are some people here who are more concerned with technical issues than they are with taking pictures. Bill - Original Message - From: "J. C. O'Connell" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, March 10, 2004 8:42 AM Subject: RE: *ist D sensor and 35mm lens resolution > If you dont mind the technical stuff your just a "point 'n shooter"! > JCO > > -- -- >J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com > -- -- > > -Original Message- > From: Rob Studdert [mailto:[EMAIL PROTECTED] > Sent: Wednesday, March 10, 2004 9:05 AM > To: [EMAIL PROTECTED] > Subject: Re: *ist D sensor and 35mm lens resolution > > > On 10 Mar 2004 at 7:41, Bill Owens wrote: > > > Oh yes, the technical issues are much more important that actually going > out and > > taking photos. > > If you sort out the technical issue before you go out taking photos you'll > be > in for less of a surprise/disappointment when you come back :-) > > Cheers, > > > Rob Studdert > HURSTVILLE AUSTRALIA > Tel +61-2-9554-4110 > UTC(GMT) +10 Hours > [EMAIL PROTECTED] > http://members.ozemail.com.au/~distudio/publications/ > Pentax user since 1986, PDMLer since 1998 > >
Re: *ist D sensor and 35mm lens resolution
Oh yes, the technical issues are much more important that actually going out and taking photos. Bill Well, the is the "Pentax-Discuss Mail List" as opposed to the "Photography-Discuss Mail List" :-) Seriously, your point is well taken. Besides, many of us lens-heads enjoy discussing the minutae of Pentax optical systems! --Mark
Re: *ist D sensor and 35mm lens resolution
- Original Message - From: "J. C. O'Connell" Subject: RE: *ist D sensor and 35mm lens resolution > If you dont mind the technical stuff your just a "point 'n shooter"! Wrongo me boy. It's not so simple as that. There is not giving a rats fart about technical stuff at all (The point and shooter). Then, theres minding the technical stuff, but not letting it get in the way (a glimmer of enlightenment). Then, theres used to give a rats fart about it until realizing that it doesn't make a whit of difference ( The enlightened photographer). Then, theres minding the technical stuff above all else (the anal retentive). I am sure there are other classes, but you get the point (perhaps). William Robb
Re: *ist D sensor and 35mm lens resolution
Hi Rob, On Wed, 10 Mar 2004 12:43:12 +1000, Rob Studdert wrote: >Has anyone here proven that DA lenses are designed to be sharper than their FF >35mm equivalents? My take on the DA lens revolution was that they are designed >to only cover an APS sensor (and secondarily designed to extract more cash from >your wallet) and are more controlled in their CA given that image sensors seem >more prone to magnify such errors. And as a consequence of the limited image >circle the lenses can be designed to be physically much smaller. I guess my >theory will be put to test when Pentax releases a DA 600/4 lens. I would guess that the 'size & weight' advantage may work out that way for wide-angles and zooms with a complex optical construction where the lens-parts are way bigger than the theoretical smallest possible aperture. (focal-length divided by f-stop) For a 600mm f/4 you are going to need a 150mm diameter front-element to get that aperture ... No reason to make DA lenses for that reason. I also have a feeling that the image circle on those longer lenses is way bigger than needed anyway. The only thing they could do is save on optical design cost since only the very center of the image-circle will be used ... Regards, JvW -- Jan van Wijk; http://www.dfsee.com/gallery
RE: *ist D sensor and 35mm lens resolution
If you dont mind the technical stuff your just a "point 'n shooter"! JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Rob Studdert [mailto:[EMAIL PROTECTED] Sent: Wednesday, March 10, 2004 9:05 AM To: [EMAIL PROTECTED] Subject: Re: *ist D sensor and 35mm lens resolution On 10 Mar 2004 at 7:41, Bill Owens wrote: > Oh yes, the technical issues are much more important that actually going out and > taking photos. If you sort out the technical issue before you go out taking photos you'll be in for less of a surprise/disappointment when you come back :-) Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
Re: *ist D sensor and 35mm lens resolution
On 10 Mar 2004 at 7:41, Bill Owens wrote: > Oh yes, the technical issues are much more important that actually going out and > taking photos. If you sort out the technical issue before you go out taking photos you'll be in for less of a surprise/disappointment when you come back :-) Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
Re: *ist D sensor and 35mm lens resolution
Oh yes, the technical issues are much more important that actually going out and taking photos. Bill > JC, > > Thanks for backing up your assertions with > your modeling approach and assumptions. Now we > can debate the merits of technical issues rather > than point fingers and talk past each other. > > --Mark > > > "J. C. O'Connell" wrote: > > Usually if not specified otherwise lpmm of a > > lens (Arial) is 50% MTF. > > > > my chart figures: > > > > [cut, snip] > > > > >
Re: *ist D sensor and 35mm lens resolution
On 10 Mar 2004 at 10:37, John Forbes wrote: > I would agree that, in practice, the necessity to blow up a *ist D image > may not matter if you are using a lens with very high resolution. > However, not all lenses, especially zooms, exhibit superb resolution, and > in such cases I am sure that the difference will be observable. Fortunately I have no lenses so poor that they exhibit resolution problems when used on the *ist D, I sold all those long ago. My only real complaints with my existing lenses are CA issues. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
Re: *ist D sensor and 35mm lens resolution
I would agree that, in practice, the necessity to blow up a *ist D image may not matter if you are using a lens with very high resolution. However, not all lenses, especially zooms, exhibit superb resolution, and in such cases I am sure that the difference will be observable. The only way to resolve this will be to conduct some comparative tests. John On Wed, 10 Mar 2004 12:28:47 +1000, Rob Studdert <[EMAIL PROTECTED]> wrote: On 10 Mar 2004 at 0:42, John Forbes wrote: I agree that film resolution also comes into play, but you cannot ignore the limits of lens resolution, as your argument suggests. If so, why would we talk about "sharpness" or have lens resolution tests. Having executed resolution tests using most of my lenses I can say that most Pentax primes deliver sufficient resolution to out perform the *ist D, that said most of my lenses are high performance primes. I think, with respect, that you are missing something. I think not :-) Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998 -- Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/
RE: *ist D sensor and 35mm lens resolution
JC, Thanks for backing up your assertions with your modeling approach and assumptions. Now we can debate the merits of technical issues rather than point fingers and talk past each other. --Mark "J. C. O'Connell" wrote: > Usually if not specified otherwise lpmm of a > lens (Arial) is 50% MTF. > > my chart figures: > > [cut, snip] >
RE: *ist D sensor and 35mm lens resolution
I missed the part where you mentioned the olympus system. The body is as big as the 35mm lens based DSLRs? Thats weird, you would have thought they could have scaled down the mount, registration, etc. Maybe the fact that the rear elements are further away from the sensor on "digital" lenses is causing the size problems of both the body and the lenses.??? JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: J. C. O'Connell [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 09, 2004 9:46 PM To: [EMAIL PROTECTED] Subject: RE: *ist D sensor and 35mm lens resolution could be because they are stuck with the 45.5mm flange registration and they are designing even shorter focal length zoom lenses, the retrofocus factor is kicking their ass. The only way they will ever get maximum performance from a APS sensor system is lenses and bodies designed from the beginning for APS sensors, i.e. the new Olympus DSLR system. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: William Robb [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 09, 2004 9:15 PM To: [EMAIL PROTECTED] Subject: Re: *ist D sensor and 35mm lens resolution - Original Message - From: "Rob Studdert" Subject: Re: *ist D sensor and 35mm lens resolution > . And as a consequence of the limited image > circle the lenses can be designed to be physically much smaller. That would account for the platter (I think it was 77mm) that goes on the front end of the DA 16-45, or the 67mm on the front of the FA 18-35. I swear, the 16-45 was nearly as big as a 645 lens. Saw the Oly E-1 system. Humping big lenses on it as well (its a pretty big pony too). I don't get it. They keep saying the lenses will get smaller, but they keep making them bigger. William Robb
RE: *ist D sensor and 35mm lens resolution
could be because they are stuck with the 45.5mm flange registration and they are designing even shorter focal length zoom lenses, the retrofocus factor is kicking their ass. The only way they will ever get maximum performance from a APS sensor system is lenses and bodies designed from the beginning for APS sensors, i.e. the new Olympus DSLR system. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: William Robb [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 09, 2004 9:15 PM To: [EMAIL PROTECTED] Subject: Re: *ist D sensor and 35mm lens resolution - Original Message - From: "Rob Studdert" Subject: Re: *ist D sensor and 35mm lens resolution > . And as a consequence of the limited image > circle the lenses can be designed to be physically much smaller. That would account for the platter (I think it was 77mm) that goes on the front end of the DA 16-45, or the 67mm on the front of the FA 18-35. I swear, the 16-45 was nearly as big as a 645 lens. Saw the Oly E-1 system. Humping big lenses on it as well (its a pretty big pony too). I don't get it. They keep saying the lenses will get smaller, but they keep making them bigger. William Robb
RE: *ist D sensor and 35mm lens resolution
Usually if not specified otherwise lpmm of a lens (Arial) is 50% MTF. my chart figures: - lens% more TOTAL RESOLUTION lp/mm of 6 Mp FF Sensor vs. 6Mp APS Sensor 200 4.877246795 190 5.41301 180 6.034483302 170 6.76054889 160 7.61545148 150 8.630661446 140 9.847515377 130 11.32098694 120 13.12512934 110 15.36099027 100 18.16814884 90 21.74139353 80 26.35410579 70 32.38840375 60 40.36516268 50 50.94376158 40 64.79643351 30 82.12404598 20 101.4719616 10 118.1540215 - is based on aerial lenslpmm and sensorlpmm using the equation: Total Resolution = Area * systemresolution^2 where1/(systemresolution)^2 = 1/lenslpmm^2 + 1/sensorresolution^2 hence when lenslpmm is fixed and less than infinity, the total resolution is always greater with FF vs APS. As the lens gets worse or is stopped down, the FF gets even better. Only a perfect lens with no diffraction limits would allow a APS sensor to resolve as good as a FF and that lens does not exist. Even then it would be as good, never better. Just the opposite with FF sensor. This isn't even taking into account the lower noise a FF sensor allows. Taking lower noise into account, you could possibly shoot FF at faster ISO speeds than APS which could improve lens performance and or camera shake factors. While there may well be no visible difference in resolution of FF vs. APS when using a superb lens at its ideal aperture, when using typical lenses and typical apertures the difference may become very visible indeed according to the numbers above. And what is most important to remember is these differences will become greater as the Mp of the sensors continue to get larger. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Mark Erickson [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 09, 2004 8:54 PM To: pentax-discuss Subject: RE: *ist D sensor and 35mm lens resolution JC, Read Rob's and my messages again. Pay particular attention to words like "significant," "insigificant," and "negligable." A camera is a signal processing system. In such a system, many different components (e.g., lens, film or sensor, physical body, tripod) may significantly influence the quality of the final output. In my engineering experience, it is typical for the limitations of one or two components to dominate. That doesn't mean that performance limitations in the other elements have no effect, just that the effects are insignificant compared to the dominant effects. A negligable difference is not the same as zero difference. I think that Rob and I are both talking about qualitative estimates, possibly educated guesses, of which component limitations dominate and by how much. You seem to keep beating the "absolute" drum, which isn't what we're talking about at all. The statement "I'm right because 0.999 is smaller than 1.0" just isn't convincing. If you want to really make your case, you need to define what you mean by resolution. 50% MTF breakpoint in lpmm? Or something else? How do you define detail? And finally, what exactly do you mean by image? Areal image? Image recorded on film? What are the imaging properties of the film itself? etc. Maybe we should use modulation transfer function (MTF) as the measure instead. Are you comfortable with frequency domain analysis? How about linearity vs nonlinearity in signal processing systems? If you make certain special assumptions about the structure of an MTF (for example that it represents a linear filter with a first-order rolloff characteristic), then you can specify its MTF at all frequencies with a single number like the 50% breakpoint in lpmm. If the MTF is more complicated (and they usually are), then the MTF response at a spatial frequency of 100 lpmm doesn't always say very much about the MTF response at, say, 50 lpmm. Then there are issues of accutance vs resolution that I really don't understand very well at all. I would be really interested to find out if, in practice, the *ist D sensor is the limiting component with, say, a 50mm prime. Norman Koren's MTF measurement methods at http://www.normankoren.com/Tutorials/MTF.html look like a good way to make some measurements --Mark JCO wrote: >I dont understand why you guys cant see that with a given, >fixed, lpmm of resolution, even the very best primes, unless it >is infinity, the cropped APS image will be less detailed than >the FF image. Very simple. And as the sensor's Mp gets bigger, >the difference between FF and APS will ge
Re: *ist D sensor and 35mm lens resolution
- Original Message - From: "Rob Studdert" Subject: Re: *ist D sensor and 35mm lens resolution > . And as a consequence of the limited image > circle the lenses can be designed to be physically much smaller. That would account for the platter (I think it was 77mm) that goes on the front end of the DA 16-45, or the 67mm on the front of the FA 18-35. I swear, the 16-45 was nearly as big as a 645 lens. Saw the Oly E-1 system. Humping big lenses on it as well (its a pretty big pony too). I don't get it. They keep saying the lenses will get smaller, but they keep making them bigger. William Robb
Re: *ist D sensor and 35mm lens resolution
- Original Message - From: "Mark Erickson" Subject: RE: *ist D sensor and 35mm lens resolution > I would be really interested to find out if, in practice, the *ist D sensor > is the limiting component with, say, a 50mm prime. Norman Koren's MTF > measurement methods at http://www.normankoren.com/Tutorials/MTF.html look > like a good way to make some measurements > It's a good way to test a system resolution at 1000:1, since that appears to be the chart he is using. Not a good way to measure how a system takes useful pictures. Sorry kids, a 1000:1 test target is not ever going to make a useful picture. William Robb
Re: *ist D sensor and 35mm lens resolution
The question is who, at least amongst folks doing photographic work, has a 72 ppi monitor anymore. Mine is closer to 100 ppi, and I am not using the highest res my system is capable of. 72 ppi is a Postscript to type size figure. It would be more properly called picas (or points per inch, though a true pica is 1/72.27 of an inch), and has little to do with what size something is displayed on your monitor. You can figure your monitors ppi by taking your horizontal resolution and dividing it by the width of the screen. Using that method I get 91 ppi for mine (1280/14) And the best possible, keeping 32bit color, is 137 ppi (1920/14). -- Jens Bladt wrote: BTW: Why does a 72 ppi computer screen picture seem as sharp/have as high a resolution as a 300 dpi print? -- graywolf http://graywolfphoto.com "You might as well accept people as they are, you are not going to be able to change them anyway."
Re: *ist D sensor and 35mm lens resolution
that's a rough approximation that makes some assumptions about the MTF curves. in particular, one critical assumption is that all of the components you are combining have the same shape of MTF curve but may differ in the spatial frequency at 10% response point. this usually isn't true, but isn't horribly wrong either. Herb... - Original Message - From: "William Robb" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, March 09, 2004 9:03 PM Subject: Re: *ist D sensor and 35mm lens resolution > I invite a look at: > http://medfmt.8k.com/mf/lenslpm.html > and look at the section: > Calculating System Resolution > where the fellow shows that system resolution is less lens dependent > than we would care to think. > > > system resolution = 1 > (lpmm) --- > ( 1/lens lpmm) + (1/film lpmm)... > Do the math.
Re: *ist D sensor and 35mm lens resolution
- Original Message - From: "J. C. O'Connell" Subject: RE: *ist D sensor and 35mm lens resolution > There are no digital lenses that are the required > 50% sharper for digital that I know of. And besides > that, there are real world diffraction limits. One of the things that I think get's lost in htese sort of discussions it the "real world". The real world isnt a place of 1000:1 toc test targets, so why look at those numbers? The real world is a much lower contrast place, a place where the 1.6:1 chart is a better place to look. This is a realm where 60 lines/mm (Fuji Across 100) is very good indeed. I invite a look at: http://medfmt.8k.com/mf/lenslpm.html and look at the section: Calculating System Resolution where the fellow shows that system resolution is less lens dependent than we would care to think. system resolution = 1 (lpmm) --- ( 1/lens lpmm) + (1/film lpmm)... Do the math. William Robb
RE: *ist D sensor and 35mm lens resolution
I think the main advantage of "Digital" designed lenses is two-fold. Smaller image circle means smaller,cheaper and/or faster lenses for same quality and more signifigantly they are designed generally with the rear most element further away from the film plane than normal so the light rays hit the sensor at a more perpendicular angle because the sensors dont perform well when the light rays are not perpendicular. There is a major trade off though, because the shorter focal lengths needed for APS combined with the futher away rear element means more severe retrofocus designs with wide angles which tends to degrade image vs a non retro design. This is what I like so much about large format wide angle lenses. They are not retrofocus and are extremely sharp and have zero distortion for the most part compared to 35mm. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Rob Studdert [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 09, 2004 9:43 PM To: [EMAIL PROTECTED] Subject: Re: *ist D sensor and 35mm lens resolution On 9 Mar 2004 at 18:24, Gonz wrote: > But if the 33mm lens was made for digital, then you would have a higher > lpmm for it and the effective sharpness would be the same. Has anyone here proven that DA lenses are designed to be sharper than their FF 35mm equivalents? My take on the DA lens revolution was that they are designed to only cover an APS sensor (and secondarily designed to extract more cash from your wallet) and are more controlled in their CA given that image sensors seem more prone to magnify such errors. And as a consequence of the limited image circle the lenses can be designed to be physically much smaller. I guess my theory will be put to test when Pentax releases a DA 600/4 lens. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
RE: *ist D sensor and 35mm lens resolution
JC, Read Rob's and my messages again. Pay particular attention to words like "significant," "insigificant," and "negligable." A camera is a signal processing system. In such a system, many different components (e.g., lens, film or sensor, physical body, tripod) may significantly influence the quality of the final output. In my engineering experience, it is typical for the limitations of one or two components to dominate. That doesn't mean that performance limitations in the other elements have no effect, just that the effects are insignificant compared to the dominant effects. A negligable difference is not the same as zero difference. I think that Rob and I are both talking about qualitative estimates, possibly educated guesses, of which component limitations dominate and by how much. You seem to keep beating the "absolute" drum, which isn't what we're talking about at all. The statement "I'm right because 0.999 is smaller than 1.0" just isn't convincing. If you want to really make your case, you need to define what you mean by resolution. 50% MTF breakpoint in lpmm? Or something else? How do you define detail? And finally, what exactly do you mean by image? Areal image? Image recorded on film? What are the imaging properties of the film itself? etc. Maybe we should use modulation transfer function (MTF) as the measure instead. Are you comfortable with frequency domain analysis? How about linearity vs nonlinearity in signal processing systems? If you make certain special assumptions about the structure of an MTF (for example that it represents a linear filter with a first-order rolloff characteristic), then you can specify its MTF at all frequencies with a single number like the 50% breakpoint in lpmm. If the MTF is more complicated (and they usually are), then the MTF response at a spatial frequency of 100 lpmm doesn't always say very much about the MTF response at, say, 50 lpmm. Then there are issues of accutance vs resolution that I really don't understand very well at all. I would be really interested to find out if, in practice, the *ist D sensor is the limiting component with, say, a 50mm prime. Norman Koren's MTF measurement methods at http://www.normankoren.com/Tutorials/MTF.html look like a good way to make some measurements --Mark JCO wrote: I dont understand why you guys cant see that with a given, fixed, lpmm of resolution, even the very best primes, unless it is infinity, the cropped APS image will be less detailed than the FF image. Very simple. And as the sensor's Mp gets bigger, the difference between FF and APS will get even greater. The other thing mentioned before is that for a given Mp of sensor, FF will outperform APS based on larger pixel area and hence lower noise, greater dynamic range. Bottom line is a FF is better than APS sensor, both sharper and less noiser, assuming Mp and lens resolution remains the same. JCO
RE: *ist D sensor and 35mm lens resolution
might as well compare to a APS *F I L M* camera since you are throwing away more than half of the 35mm film image. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Rob Studdert [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 09, 2004 9:24 PM To: [EMAIL PROTECTED] Subject: RE: *ist D sensor and 35mm lens resolution On 9 Mar 2004 at 19:46, J. C. O'Connell wrote: > how can you use the same lens when there is a 1.5 crop factor? > It's only fair to use a lens 1.5 times longer with film and then > compare. Maybe a good zoom? Can't we just forget the crop factor and compare the inside area of the 35mm frame to the APS sized frame? Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
Re: *ist D sensor and 35mm lens resolution
On 9 Mar 2004 at 18:24, Gonz wrote: > But if the 33mm lens was made for digital, then you would have a higher > lpmm for it and the effective sharpness would be the same. Has anyone here proven that DA lenses are designed to be sharper than their FF 35mm equivalents? My take on the DA lens revolution was that they are designed to only cover an APS sensor (and secondarily designed to extract more cash from your wallet) and are more controlled in their CA given that image sensors seem more prone to magnify such errors. And as a consequence of the limited image circle the lenses can be designed to be physically much smaller. I guess my theory will be put to test when Pentax releases a DA 600/4 lens. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
Re: *ist D sensor and 35mm lens resolution
On 10 Mar 2004 at 0:42, John Forbes wrote: > I agree that film resolution also comes into play, but you cannot ignore > the limits of lens resolution, as your argument suggests. If so, why > would we talk about "sharpness" or have lens resolution tests. Having executed resolution tests using most of my lenses I can say that most Pentax primes deliver sufficient resolution to out perform the *ist D, that said most of my lenses are high performance primes. > I think, with respect, that you are missing something. I think not :-) Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
RE: *ist D sensor and 35mm lens resolution
On 9 Mar 2004 at 19:46, J. C. O'Connell wrote: > how can you use the same lens when there is a 1.5 crop factor? > It's only fair to use a lens 1.5 times longer with film and then > compare. Maybe a good zoom? Can't we just forget the crop factor and compare the inside area of the 35mm frame to the APS sized frame? Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
RE: *ist D sensor and 35mm lens resolution
What is FF (full frame?) and MFG (Medium Format ...?)?? I will soon be posting tests (as a PAW): My Penax lenses and neg. film scanned to 1200, 3200 and 6400 ppi - vs. my SONY F717 (5MP) camera, using a 6x8mm chip. I shot the same scene, at same ISO (200) using the same (equivalent) focal lengths on at the same time. It's allready clear, that the resolution of the 3200 and 6400 scans are higher, than those of the 5MP camera. No questions about that. But the big question is: Are the pictures any better? Unfortunaltly www.fotopic.net doesn't work right now. But I'll get back to that shortly. BTW: Why does a 72 ppi computer screen picture seem as sharp/have as high a resolution as a 300 dpi print? All the best Jens Bladt mailto:[EMAIL PROTECTED] http://hjem.get2net.dk/bladt -Oprindelig meddelelse- Fra: J. C. O'Connell [mailto:[EMAIL PROTECTED] Sendt: 10. marts 2004 00:48 Til: [EMAIL PROTECTED] Emne: RE: *ist D sensor and 35mm lens resolution I dont know about your last statement, the higher the density (smaller the circuits) the more defects will occur in MFG, and hense lower yield/higher cost for a much denser chip of the same area. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Rob Studdert [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 09, 2004 7:35 PM To: [EMAIL PROTECTED] Subject: RE: *ist D sensor and 35mm lens resolution On 9 Mar 2004 at 18:24, J. C. O'Connell wrote: > Oh no, very mistaken! Yes of course a 14mp FF sensor will be better than > a 6Mp FF sensor in terms of resolution, but a 6MP FF sensor is DEFINATELY better > than a 6MP APS sensor, not only will the image be sharper due to lens > limitations, > the FF image will be less noiser due to larger pixel area. The only > downside > to FF vs. APS for a given Mp is cost. John, you're not listening, many of us are very happy with the noise performance and latitude afforded by our puny APS sized 6MP sensors, many of us however would like full frame coverage. The cost is mainly a function of the substrate size not the density, CCD sensors of any density have huge structures compared with most any other type of VLSI semiconductor in production. In other words the cost to produce a 6MP or 14MP FF sensor is going to be similar. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
RE: *ist D sensor and 35mm lens resolution
On 9 Mar 2004 at 18:48, J. C. O'Connell wrote: > I dont know about your last statement, the higher the density > (smaller the circuits) the more defects will occur in MFG, > and hense lower yield/higher cost for a much denser chip of the > same area. What was alluding to was that the size of imperfections has been reduced with the development of many other very high density chips, so much so that generally flaws are likely many many time smaller than a pixel site even on a small relatively dense sensor. Yield rates have been improved upon significantly in the last 10 years. http://www.wired.com/wired/archive/4.06/money.html Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
RE: *ist D sensor and 35mm lens resolution
heres a repost of the data on a 6Mp FF sensor vs a 6MP APS sensor vs. lens resolution. - lens% more TOTAL RESOLUTION lp/mm of FF Sensor vs. APS Sensor 200 4.877246795 190 5.41301 180 6.034483302 170 6.76054889 160 7.61545148 150 8.630661446 140 9.847515377 130 11.32098694 120 13.12512934 110 15.36099027 100 18.16814884 90 21.74139353 80 26.35410579 70 32.38840375 60 40.36516268 50 50.94376158 40 64.79643351 30 82.12404598 20 101.4719616 10 118.1540215 - As you can see, once the lens resolution gets below say 140 lpmm, there is at least a 10% improvement in going FF and that increases dramatically as the lens resolution goes down. And dont forget even perfect lenses cannot acheive the highest numbers on the chart when stopped down for greater DOF for diffraction reasons. It seems to me that unless you are using the finest lenses at the ideal aperture, you are going to get signifigant resolution improvement by going FF vs. APS for a 6Mp sensor. Couple that with better noise characteristics of a FF and the ability of your wide lenses to remain wide, I dont really see any advantage of APS other than cost and/or maybe smaller size of the camera and lenses (if you bought special APS lenses instead of 35mm lenses). JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com
RE: *ist D sensor and 35mm lens resolution
I dont know about your last statement, the higher the density (smaller the circuits) the more defects will occur in MFG, and hense lower yield/higher cost for a much denser chip of the same area. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Rob Studdert [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 09, 2004 7:35 PM To: [EMAIL PROTECTED] Subject: RE: *ist D sensor and 35mm lens resolution On 9 Mar 2004 at 18:24, J. C. O'Connell wrote: > Oh no, very mistaken! Yes of course a 14mp FF sensor will be better than > a 6Mp FF sensor in terms of resolution, but a 6MP FF sensor is DEFINATELY better > than a 6MP APS sensor, not only will the image be sharper due to lens > limitations, > the FF image will be less noiser due to larger pixel area. The only > downside > to FF vs. APS for a given Mp is cost. John, you're not listening, many of us are very happy with the noise performance and latitude afforded by our puny APS sized 6MP sensors, many of us however would like full frame coverage. The cost is mainly a function of the substrate size not the density, CCD sensors of any density have huge structures compared with most any other type of VLSI semiconductor in production. In other words the cost to produce a 6MP or 14MP FF sensor is going to be similar. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
RE: *ist D sensor and 35mm lens resolution
On 9 Mar 2004 at 18:24, J. C. O'Connell wrote: > give me a lpmm figure, and I will post the difference a FF sensor will make. I > only calculated data for a 6Mp sensor so far, so let's assume that. Sorry I can't help, I've never seen any aerial resolution tests for any Pentax lenses. Practically though I've measured the said lens resolution on a *ist D with a high resolution lens testing chart under ideal conditions and achieved no more than 44.6lpmm. You can work out the rest. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
RE: *ist D sensor and 35mm lens resolution
> Bottom line is a FF is better than > APS sensor, both sharper and less noiser, assuming Mp and lens > resolution remains the same. Sure but by what practical degree? like I said, quote me a lpmm figure and I will post the resolution improvement by going to FF vs APS. (I only have data on 6Mp sensors). JCO
RE: *ist D sensor and 35mm lens resolution
On 9 Mar 2004 at 18:24, J. C. O'Connell wrote: > Oh no, very mistaken! Yes of course a 14mp FF sensor will be better than > a 6Mp FF sensor in terms of resolution, but a 6MP FF sensor is DEFINATELY better > than a 6MP APS sensor, not only will the image be sharper due to lens > limitations, > the FF image will be less noiser due to larger pixel area. The only > downside > to FF vs. APS for a given Mp is cost. John, you're not listening, many of us are very happy with the noise performance and latitude afforded by our puny APS sized 6MP sensors, many of us however would like full frame coverage. The cost is mainly a function of the substrate size not the density, CCD sensors of any density have huge structures compared with most any other type of VLSI semiconductor in production. In other words the cost to produce a 6MP or 14MP FF sensor is going to be similar. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
RE: *ist D sensor and 35mm lens resolution
On 9 Mar 2004 at 18:16, J. C. O'Connell wrote: > I dont understand why you guys cant see that with a given, > fixed, lpmm of resolution, even the very best primes, unless it > is infinity, the cropped APS image will be less detailed than > the FF image. Very simple. And as the sensor's Mp gets bigger, > the difference between FF and APS will get even greater. All that I understand of sampling theorem is undermined by your suggestions. What I am saying is any difference WRT to resolution in each case will generally be so small as to be insignificant particularly if we are talking prints as the final output medium. Very simple. > The other thing mentioned before is that for a given Mp of sensor, > FF will outperform APS based on larger pixel area and hence lower > noise, greater dynamic range. I think we all are undeniably aware of these factors John. > Bottom line is a FF is better than > APS sensor, both sharper and less noiser, assuming Mp and lens > resolution remains the same. Sure but by what practical degree? Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
RE: *ist D sensor and 35mm lens resolution
Subject: RE: *ist D sensor and 35mm lens resolution On 9 Mar 2004 at 17:59, J. C. O'Connell wrote: > wrong, > > I posted data on this about a month ago. Even with a 6Mp sensor > a FF sensor will ALWAYS yeild higher total resolution image than > a APS sensor as long as the lens resolution is not infinite and > it never is. The WILL be an ABSOLUTE difference. But as the Mp > of the sensor goes down and the resolution of the lenses go up, the > difference in total resolution of FF vs. APS will be smaller. OK, so what would be the percentage improvement when using say an A50/1.5 at f5.6? === give me a lpmm figure, and I will post the difference a FF sensor will make. I only calculated data for a 6Mp sensor so far, so let's assume that. === > But as we can all see, the Mp of the sensors are going up and the > lenses resolution are essentially fixed (not improving), thus the > case for FF being better than APS is becoming more true every day. > The other thing is that unless you are using the very finest lenses, > which often cost more than a DSLR body, there is even more to be gained > by going FF. I guess what I am saying is that I think it would be more > cost effective to buy an more expensive FF body than to go with APS sensor > and have to buy every lens super state of the art. I would much rather have a FF sensor of 14MP than one with 6MP density. The only practical advantage to using a FF 6MP sensor would be that the lenses AOV would be compatible with film bodies. Cheers, Rob Studdert == Oh no, very mistaken! Yes of course a 14mp FF sensor will be better than a 6Mp FF sensor in terms of resolution, but a 6MP FF sensor is DEFINATELY better than a 6MP APS sensor, not only will the image be sharper due to lens limitations, the FF image will be less noiser due to larger pixel area. The only downside to FF vs. APS for a given Mp is cost. JCO ===
RE: *ist D sensor and 35mm lens resolution
I dont understand why you guys cant see that with a given, fixed, lpmm of resolution, even the very best primes, unless it is infinity, the cropped APS image will be less detailed than the FF image. Very simple. And as the sensor's Mp gets bigger, the difference between FF and APS will get even greater. The other thing mentioned before is that for a given Mp of sensor, FF will outperform APS based on larger pixel area and hence lower noise, greater dynamic range. Bottom line is a FF is better than APS sensor, both sharper and less noiser, assuming Mp and lens resolution remains the same. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Mark Erickson [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 09, 2004 6:00 PM To: pentax-discuss Subject: RE: *ist D sensor and 35mm lens resolution "Rob Studdert" <[EMAIL PROTECTED]> wrote: > >On 9 Mar 2004 at 16:29, J. C. O'Connell wrote: > >> I agree with John on this. It is very obvious that unless you have >> lenses with infinite resolution (and you dont), that capturing >> ALL of the image from a 50mm lens is going to be sharper than >> capturing a center crop from a 33mm lens. ( 1.5 crop factor sensor) >> This is assuming both the 50mm and the 33mm have the same lpmm >> and it is not infinite. > >I don't subscribe to this theory, I believe that your assumption >regarding lens resolution limits is flawed. > >The fact is that most lenses have an aerial resolution >many times higher than the theoretical maximum resolution >of the sensor therefore their part in the overall system >resolution dwindles into virtual insignificance. I agree with Rob provided we're talking about high-quality lenses (e.g., a 50mm prime on a full-frame camera and a 35mm prime on an APS-frame camera). If instead, you consider an older 28-200 super-zoom shot wide open, then you may see significant degradation due to the crop factor effect. In practice, I would expect things like focus error and insufficient support to often be more significant than the raw lens resolution. --Mark
RE: *ist D sensor and 35mm lens resolution
On 9 Mar 2004 at 17:59, J. C. O'Connell wrote: > wrong, > > I posted data on this about a month ago. Even with a 6Mp sensor > a FF sensor will ALWAYS yeild higher total resolution image than > a APS sensor as long as the lens resolution is not infinite and > it never is. The WILL be an ABSOLUTE difference. But as the Mp > of the sensor goes down and the resolution of the lenses go up, the > difference in total resolution of FF vs. APS will be smaller. OK, so what would be the percentage improvement when using say an A50/1.5 at f5.6? > But as we can all see, the Mp of the sensors are going up and the > lenses resolution are essentially fixed (not improving), thus the > case for FF being better than APS is becoming more true every day. > The other thing is that unless you are using the very finest lenses, > which often cost more than a DSLR body, there is even more to be gained > by going FF. I guess what I am saying is that I think it would be more > cost effective to buy an more expensive FF body than to go with APS sensor > and have to buy every lens super state of the art. I would much rather have a FF sensor of 14MP than one with 6MP density. The only practical advantage to using a FF 6MP sensor would be that the lenses AOV would be compatible with film bodies. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
RE: *ist D sensor and 35mm lens resolution
"Rob Studdert" <[EMAIL PROTECTED]> wrote: On 9 Mar 2004 at 16:29, J. C. O'Connell wrote: I agree with John on this. It is very obvious that unless you have lenses with infinite resolution (and you dont), that capturing ALL of the image from a 50mm lens is going to be sharper than capturing a center crop from a 33mm lens. ( 1.5 crop factor sensor) This is assuming both the 50mm and the 33mm have the same lpmm and it is not infinite. I don't subscribe to this theory, I believe that your assumption regarding lens resolution limits is flawed. The fact is that most lenses have an aerial resolution many times higher than the theoretical maximum resolution of the sensor therefore their part in the overall system resolution dwindles into virtual insignificance. I agree with Rob provided we're talking about high-quality lenses (e.g., a 50mm prime on a full-frame camera and a 35mm prime on an APS-frame camera). If instead, you consider an older 28-200 super-zoom shot wide open, then you may see significant degradation due to the crop factor effect. In practice, I would expect things like focus error and insufficient support to often be more significant than the raw lens resolution. --Mark
RE: *ist D sensor and 35mm lens resolution
wrong, I posted data on this about a month ago. Even with a 6Mp sensor a FF sensor will ALWAYS yeild higher total resolution image than a APS sensor as long as the lens resolution is not infinite and it never is. The WILL be an ABSOLUTE difference. But as the Mp of the sensor goes down and the resolution of the lenses go up, the difference in total resolution of FF vs. APS will be smaller. But as we can all see, the Mp of the sensors are going up and the lenses resolution are essentially fixed (not improving), thus the case for FF being better than APS is becoming more true every day. The other thing is that unless you are using the very finest lenses, which often cost more than a DSLR body, there is even more to be gained by going FF. I guess what I am saying is that I think it would be more cost effective to buy an more expensive FF body than to go with APS sensor and have to buy every lens super state of the art. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Rob Studdert [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 09, 2004 5:48 PM To: [EMAIL PROTECTED] Subject: RE: *ist D sensor and 35mm lens resolution On 9 Mar 2004 at 16:29, J. C. O'Connell wrote: > I agree with John on this. It is very obvious that unless you have > lenses with infinite resolution (and you dont), that capturing > ALL of the image from a 50mm lens is going to be sharper than > capturing a center crop from a 33mm lens. ( 1.5 crop factor sensor) > This is assuming both the 50mm and the 33mm have the same lpmm > and it is not infinite. I don't subscribe to this theory, I believe that your assumption regarding lens resolution limits is flawed. The fact is that most lenses have an aerial resolution many times higher than the theoretical maximum resolution of the sensor therefore their part in the overall system resolution dwindles into virtual insignificance. If a FF sensor and an APS sensor have the same number of pixels (differing pixel sizes) then there will be no absolute difference in the sharpness of the final print when good quality lenses of the appropriate FL are used to produce the same AOV on each sensor. The advantages of a larger pixel site area are greater sensitivity and lower noise, ie greater capture latitude. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
RE: *ist D sensor and 35mm lens resolution
On 9 Mar 2004 at 16:29, J. C. O'Connell wrote: > I agree with John on this. It is very obvious that unless you have > lenses with infinite resolution (and you dont), that capturing > ALL of the image from a 50mm lens is going to be sharper than > capturing a center crop from a 33mm lens. ( 1.5 crop factor sensor) > This is assuming both the 50mm and the 33mm have the same lpmm > and it is not infinite. I don't subscribe to this theory, I believe that your assumption regarding lens resolution limits is flawed. The fact is that most lenses have an aerial resolution many times higher than the theoretical maximum resolution of the sensor therefore their part in the overall system resolution dwindles into virtual insignificance. If a FF sensor and an APS sensor have the same number of pixels (differing pixel sizes) then there will be no absolute difference in the sharpness of the final print when good quality lenses of the appropriate FL are used to produce the same AOV on each sensor. The advantages of a larger pixel site area are greater sensitivity and lower noise, ie greater capture latitude. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
RE: *ist D sensor and 35mm lens resolution
I agree with John on this. It is very obvious that unless you have lenses with infinite resolution (and you dont), that capturing ALL of the image from a 50mm lens is going to be sharper than capturing a center crop from a 33mm lens. ( 1.5 crop factor sensor) This is assuming both the 50mm and the 33mm have the same lpmm and it is not infinite. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: John Forbes [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 09, 2004 4:08 PM To: [EMAIL PROTECTED] Subject: Re: *ist D sensor and 35mm lens resolution Surely this is quite simple. With the *ist D you are getting a crop of the normal image that you would get with a 35mm film camera. Therefore, to view the image at the same size, you have to blow it up more, and thereby lose effective resolution. John On Tue, 09 Mar 2004 14:40:13 -0500, graywolf <[EMAIL PROTECTED]> wrote: > There are two opposing things that control lens resolution. There are > laws of physics involved that give a maximum theoretical capability that > any lens can have. > > Basically those two things are diffraction, and aberrations. They are > opposing because closing a lens down increases diffraction, and openning > it up increases aberrations. A lens is said to be diffraction limited > when all the aberrations are corrected at the widest apperture. That is > fairly easy to do with something like the old Kodak Ektar 200mm/f7.7 > (covers 4x5, well actually 5x7 but it is not diffraction limited on 5x7) > because the maximum aperture is only about f8. The French made Kinoptik > 100mm/f2.0 (covers 35mm)which is also supposed to be diffraction limited > is a very expensive lens as it is much harder to do with a fast lens. It > is also harder to do with wider fields of view which is why the Ektar is > not diffraction limited on 5x7. > > The wider the aperture the higher the resolution, as long as the > aberrations are fully corrected. The Kinoptik with its 50mm aperture has > an aerial resolution of about 400 lines per millimeter, the Ektar with > 1/2 that has about 200 lpm. > > Now it is easier to make a fully corrected large aperture lens at > shorter focal lengths, so that is why they claim shorter lenses have > higher resolution. But that unless you are willing to pay astronomical > amounts for diffraction limited lenses is only theoretically, especially > today when they can make large lenses to the same tolerances as smaller > ones. > > Note: Those high resolution numbers I mentioned are for aerial images, > examined with a microscope (also they are an approximation as I am too > lazy to look up or calculate the actual figures). Overall resolution on > film or sensor will alway be lower than the lowest resolution in the > system which is usually the film or sensor resolution. As an example, > with that Kinoptik (400 lpm), on Tech Pan (200 lpm) you would get > something like 150 lpm overall, which is about the best your are going > to do with what I know is available out there. > > Also note that by the time you make your print that near impossible 150 > lpm on 35mm is only equal to an easy to get 37.5 lpm on 4x5 which should > put the whole thing into perspective. > > -- Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/
Re: *ist D sensor and 35mm lens resolution
Surely this is quite simple. With the *ist D you are getting a crop of the normal image that you would get with a 35mm film camera. Therefore, to view the image at the same size, you have to blow it up more, and thereby lose effective resolution. John On Tue, 09 Mar 2004 14:40:13 -0500, graywolf <[EMAIL PROTECTED]> wrote: There are two opposing things that control lens resolution. There are laws of physics involved that give a maximum theoretical capability that any lens can have. Basically those two things are diffraction, and aberrations. They are opposing because closing a lens down increases diffraction, and openning it up increases aberrations. A lens is said to be diffraction limited when all the aberrations are corrected at the widest apperture. That is fairly easy to do with something like the old Kodak Ektar 200mm/f7.7 (covers 4x5, well actually 5x7 but it is not diffraction limited on 5x7) because the maximum aperture is only about f8. The French made Kinoptik 100mm/f2.0 (covers 35mm)which is also supposed to be diffraction limited is a very expensive lens as it is much harder to do with a fast lens. It is also harder to do with wider fields of view which is why the Ektar is not diffraction limited on 5x7. The wider the aperture the higher the resolution, as long as the aberrations are fully corrected. The Kinoptik with its 50mm aperture has an aerial resolution of about 400 lines per millimeter, the Ektar with 1/2 that has about 200 lpm. Now it is easier to make a fully corrected large aperture lens at shorter focal lengths, so that is why they claim shorter lenses have higher resolution. But that unless you are willing to pay astronomical amounts for diffraction limited lenses is only theoretically, especially today when they can make large lenses to the same tolerances as smaller ones. Note: Those high resolution numbers I mentioned are for aerial images, examined with a microscope (also they are an approximation as I am too lazy to look up or calculate the actual figures). Overall resolution on film or sensor will alway be lower than the lowest resolution in the system which is usually the film or sensor resolution. As an example, with that Kinoptik (400 lpm), on Tech Pan (200 lpm) you would get something like 150 lpm overall, which is about the best your are going to do with what I know is available out there. Also note that by the time you make your print that near impossible 150 lpm on 35mm is only equal to an easy to get 37.5 lpm on 4x5 which should put the whole thing into perspective. -- Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/
Re: *ist D sensor and 35mm lens resolution
There are two opposing things that control lens resolution. There are laws of physics involved that give a maximum theoretical capability that any lens can have. Basically those two things are diffraction, and aberrations. They are opposing because closing a lens down increases diffraction, and openning it up increases aberrations. A lens is said to be diffraction limited when all the aberrations are corrected at the widest apperture. That is fairly easy to do with something like the old Kodak Ektar 200mm/f7.7 (covers 4x5, well actually 5x7 but it is not diffraction limited on 5x7) because the maximum aperture is only about f8. The French made Kinoptik 100mm/f2.0 (covers 35mm)which is also supposed to be diffraction limited is a very expensive lens as it is much harder to do with a fast lens. It is also harder to do with wider fields of view which is why the Ektar is not diffraction limited on 5x7. The wider the aperture the higher the resolution, as long as the aberrations are fully corrected. The Kinoptik with its 50mm aperture has an aerial resolution of about 400 lines per millimeter, the Ektar with 1/2 that has about 200 lpm. Now it is easier to make a fully corrected large aperture lens at shorter focal lengths, so that is why they claim shorter lenses have higher resolution. But that unless you are willing to pay astronomical amounts for diffraction limited lenses is only theoretically, especially today when they can make large lenses to the same tolerances as smaller ones. Note: Those high resolution numbers I mentioned are for aerial images, examined with a microscope (also they are an approximation as I am too lazy to look up or calculate the actual figures). Overall resolution on film or sensor will alway be lower than the lowest resolution in the system which is usually the film or sensor resolution. As an example, with that Kinoptik (400 lpm), on Tech Pan (200 lpm) you would get something like 150 lpm overall, which is about the best your are going to do with what I know is available out there. Also note that by the time you make your print that near impossible 150 lpm on 35mm is only equal to an easy to get 37.5 lpm on 4x5 which should put the whole thing into perspective. -- graywolf http://graywolfphoto.com "You might as well accept people as they are, you are not going to be able to change them anyway."
Re: *ist D sensor and 35mm lens resolution
- Original Message - From: "Greg Lovern" Subject: *ist D sensor and 35mm lens resolution I think Rob figured the sensor resolution to be around 45 lpmm. This is pretty close to what a good lens will resolve, and also fairly close to what film will resolve under normal picture taking situations. Lens resolution is tied more to lens design and quality of materials and build than to format. William Robb > The *ist D's sensor has about 43% of the area of a 35mm film frame (369 > square mm compared to 864 square mm). Lenses don't have infinite > resolution; instead they have resolution limits for each aperature. Does > it follow that a 35mm film lens' resolution, when used on the *ist D, will > be 43% of its resolution on a 35mm film camera? (And conversely, that its > resolution on a 35mm film camera would be 234% of its resolution on the > *ist D?) > > If a given DA lens were to be as similar as reasonably possible to a given > 35mm lens, with the sole exception that it's image projected the same > resolution onto the smaller area of the *ist D's sensor, would the sensor > be able to capture 234% as much resolution as it would with the 35mm film > lens? > > If a very sharp lens, such as Pentax's sharpest 50mm lenses (past or > present), loses 57% of its resolution when used on the *ist D, is it still > a very sharp lens? > > I plan to get an *ist D soon no matter what answers I get to these > questions. I'm just wondering what the potential is for DA lenses, all > else being equal, to be sharper on the *ist D than 35mm film lenses. > > > Thanks, > > Greg > >
Re: *ist D sensor and 35mm lens resolution
On 8 Mar 2004 at 23:54, Greg Lovern wrote: > Does > it follow that a 35mm film lens' resolution, when used on the *ist D, will > be 43% of its resolution on a 35mm film camera? (And conversely, that its > resolution on a 35mm film camera would be 234% of its resolution on the > *ist D?) Lens resolution remains the same, system resolution however is a function of the lens resolution and the sensor resolution. Practically the system resolution of the *ist D using the best optics is about 45lpmm. > If a given DA lens were to be as similar as reasonably possible to a given > 35mm lens, with the sole exception that it's image projected the same > resolution onto the smaller area of the *ist D's sensor, would the sensor > be able to capture 234% as much resolution as it would with the 35mm film > lens? No, see above. > If a very sharp lens, such as Pentax's sharpest 50mm lenses (past or > present), loses 57% of its resolution when used on the *ist D, is it still > a very sharp lens? Still sharp but more detail could easily be resolved on most any film. > I plan to get an *ist D soon no matter what answers I get to these > questions. I'm just wondering what the potential is for DA lenses, all > else being equal, to be sharper on the *ist D than 35mm film lenses. One would hope that they should be optimised to limit chromatic aberrations at wide angles of view, most other parameters are well served by existing K-mount lenses. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
*ist D sensor and 35mm lens resolution
The *ist D's sensor has about 43% of the area of a 35mm film frame (369 square mm compared to 864 square mm). Lenses don't have infinite resolution; instead they have resolution limits for each aperature. Does it follow that a 35mm film lens' resolution, when used on the *ist D, will be 43% of its resolution on a 35mm film camera? (And conversely, that its resolution on a 35mm film camera would be 234% of its resolution on the *ist D?) If a given DA lens were to be as similar as reasonably possible to a given 35mm lens, with the sole exception that it's image projected the same resolution onto the smaller area of the *ist D's sensor, would the sensor be able to capture 234% as much resolution as it would with the 35mm film lens? If a very sharp lens, such as Pentax's sharpest 50mm lenses (past or present), loses 57% of its resolution when used on the *ist D, is it still a very sharp lens? I plan to get an *ist D soon no matter what answers I get to these questions. I'm just wondering what the potential is for DA lenses, all else being equal, to be sharper on the *ist D than 35mm film lenses. Thanks, Greg
Re: Lens resolution
It's a function of both. All lenses are imperfect, all films are imperfect Both blur the lines, the difference between a good high resolution lens and a poor one is easy to see. At 06:49 PM 9/14/03 +0200, you wrote: Bob Blakely: I've seen people here talk about the resolution of lenses. I fully understand the physics behind resolution of both digital image sensors and film, but what really is resolution when talking about lenses? Lens resolution is defined as the number of resolution target lines per millimeter that can be discerned in the film. Discerned means that the individual lines from the target can be seen, however slight and fuzzy. Where the lines cannot be discerned, a (theoretically) 50% gray is observed. The lines are black and the spaces between parallel lines are white and of the same width as the lines. To me, this sounds like this would be a property of the film, not a property of the lens? I mean, with higher definition film, a film with finer grain or whatever, it would be possible to show more detail, wouldn't it? Or is it really the lens itself that blurs the lines? anders - http://anders.hultman.nu/ To grasp the true meaning of socialism, imagine a world where everything is designed by the post office, even the sleaze. O'Rourke, P.J.
Re: Lens resolution
- Original Message - From: "J. C. O'Connell" Subject: RE: Lens resolution > Subject: Re: Lens resolution > Last time I checked Tmax 100 was > 200 lp/mm according to Kodak Specs > with a high contrast target I don't take a lot of pictures of test targets, I am more of a landscape kind of guy. For this purpose, the 1.6:1 toc figure more closely resembles an average scene contrast. William Robb
RE: Lens resolution
ratio J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: J. C. O'Connell [mailto:[EMAIL PROTECTED] Sent: Monday, September 15, 2003 5:30 PM To: [EMAIL PROTECTED] Subject: RE: Lens resolution I know mtf is a curve, but to specify "resolution" one but also specify at what ration of black to white contrast is diminished to. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Bob Blakely [mailto:[EMAIL PROTECTED] Sent: Monday, September 15, 2003 4:38 PM To: [EMAIL PROTECTED] Subject: RE: Lens resolution wrong! You must have at least *two* black lines separated by white space or at least two white lines separated by a black space. The edge of resolution is defined as the boundary distance where the two lines can just (almost) be discerned as separate vs. one line or where the two lines just (almost) merge to one line or where a series of equally spaced & sized black lines and white spaces merge to 50% gray without spatial ripple. It's the same number and it's not the same as the MTF or Modulation Transfer Function. It is only one point on the function. > From: J. C. O'Connell [mailto:[EMAIL PROTECTED] > > I dont agree with the final conclusion in this post. > resolution is detemined by 1 black line next to > one white line and determining a reference of how thin they > can be made before the black and white fade into a middle grey > value, MTF to be more specific... > JCO > > Bob Blakely wrote: > > > > Logically, because for one line to exist, it must have a > background. If it > > is thought of as a black line then it has a white background. If it is > > thought of as a white line then it has a black background. By > saying that > > the "pair" is a black line and a white line, then it is not possible to > draw > > one line pair! > > > > No one draws a black line on a white piece of paper and claims > it's a line > > pair! > > > > No one draws two black lines parallel together on a sheet of paper and > > claims it's four lines! > > > > No one draws 100 black lines parallel together on a sheet of paper and > > claims it's 200 lines! > > Thank you Bob! > That says it, doesn't it? > > > I'm starting to become convinced that the idea of "line pairs per mm" > > started as the result of some anal retentive who, for the sake > of argument > > alone, claimed that one could think of the resolution target as white > lines > > on a black background just as well as black lines on a white background > > (true enough). Either he or others decided that it was somehow "more > > scientific, more intellectual or whatever" to start calling > both the black > > area and the white area as lines. To me, this leap is nonsense. I am > quickly > > beginning to believe that "line pairs per millimeter" is > nothing more than > a > > pseudo intellectual attempt to sound more knowledgeable about the topic, > and > > (in fact) is really the same as lines per millimeter. Indeed, a 10^100 > > search of the web shows that the terms are often used > interchangeably and > > refer to the same number. > > [snipped] > > Resolution as spoken of by astronomers works with points of light > against a very black background, and they talk about separating (or > "resolving") known twin stars, which have known separations, and it's a > test of their system to see if they can separate the two -- see two > distinct stars. > This brings up talk of airy discs and such, but there's no talk about > white stars and black stars, there's only two close together white stars > against the black firmament. > > So it seems camera lens resolution should be just the lines themselves. > If you prefer, black lines drawn on white or gray paper. > And like astronomers do, it's a test to see how close together those > parallel lines can be and still be resolved into a distinct pair of > black lines, or whether it's a bar-shaped smudge. > > That sort of says it all, far as I'm concerned. > > keith whaley > > >
Re: Lens resolution
> > > > "J. C. O'Connell" wrote: > > > > I dont agree with the final conclusion in this post. > > resolution is detemined by 1 black line next to > > one white line and determining a reference of how thin they > > can be made before the black and white fade into a middle grey > > value, MTF to be more specific... > > JCO > > I think the only objection that could be raised here is, I maintain the > white you see is a space, not a "line." > The white space merely represents how far apart the black lines are, > without which one would never be able to tell. You need something that > gives good contrast. White is logical, gray is okay too, if the contrast > is high enough. > The trick is, getting the line's weight or width to be the same size as > the separation _between_ the lines, so as to make spaces and lines of > equal width as they both get smaller.. > But, that's not a problem, just a condition of the testing procedure. > > Finally, it seems we're all in agreement in principle, except for the > nomenclature used, aren't we? > I call the white stuff a space, you call it a line, but we both have 100 > black lines per millimeter, or whatever value obtains. Not so? Sort of, except for the fact that if you can resolve 100 black lines per mm on a white background you'll only manage a lesser number against a grey background. A specification that only mentions one component, and makes no mention of the contrast ratio between the two components, is flawed. That's what you are doing if you only describe the spacing between the black lines. If you are talking about the contrast ratio you need two pieces; the black part we all agree on, and the interleaved part. In other words there are a pair of lines - one black, one white. And the colour of each is equally important.
RE: Lens resolution
I know mtf is a curve, but to specify "resolution" one but also specify at what ration of black to white contrast is diminished to. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Bob Blakely [mailto:[EMAIL PROTECTED] Sent: Monday, September 15, 2003 4:38 PM To: [EMAIL PROTECTED] Subject: RE: Lens resolution wrong! You must have at least *two* black lines separated by white space or at least two white lines separated by a black space. The edge of resolution is defined as the boundary distance where the two lines can just (almost) be discerned as separate vs. one line or where the two lines just (almost) merge to one line or where a series of equally spaced & sized black lines and white spaces merge to 50% gray without spatial ripple. It's the same number and it's not the same as the MTF or Modulation Transfer Function. It is only one point on the function. > From: J. C. O'Connell [mailto:[EMAIL PROTECTED] > > I dont agree with the final conclusion in this post. > resolution is detemined by 1 black line next to > one white line and determining a reference of how thin they > can be made before the black and white fade into a middle grey > value, MTF to be more specific... > JCO > > Bob Blakely wrote: > > > > Logically, because for one line to exist, it must have a > background. If it > > is thought of as a black line then it has a white background. If it is > > thought of as a white line then it has a black background. By > saying that > > the "pair" is a black line and a white line, then it is not possible to > draw > > one line pair! > > > > No one draws a black line on a white piece of paper and claims > it's a line > > pair! > > > > No one draws two black lines parallel together on a sheet of paper and > > claims it's four lines! > > > > No one draws 100 black lines parallel together on a sheet of paper and > > claims it's 200 lines! > > Thank you Bob! > That says it, doesn't it? > > > I'm starting to become convinced that the idea of "line pairs per mm" > > started as the result of some anal retentive who, for the sake > of argument > > alone, claimed that one could think of the resolution target as white > lines > > on a black background just as well as black lines on a white background > > (true enough). Either he or others decided that it was somehow "more > > scientific, more intellectual or whatever" to start calling > both the black > > area and the white area as lines. To me, this leap is nonsense. I am > quickly > > beginning to believe that "line pairs per millimeter" is > nothing more than > a > > pseudo intellectual attempt to sound more knowledgeable about the topic, > and > > (in fact) is really the same as lines per millimeter. Indeed, a 10^100 > > search of the web shows that the terms are often used > interchangeably and > > refer to the same number. > > [snipped] > > Resolution as spoken of by astronomers works with points of light > against a very black background, and they talk about separating (or > "resolving") known twin stars, which have known separations, and it's a > test of their system to see if they can separate the two -- see two > distinct stars. > This brings up talk of airy discs and such, but there's no talk about > white stars and black stars, there's only two close together white stars > against the black firmament. > > So it seems camera lens resolution should be just the lines themselves. > If you prefer, black lines drawn on white or gray paper. > And like astronomers do, it's a test to see how close together those > parallel lines can be and still be resolved into a distinct pair of > black lines, or whether it's a bar-shaped smudge. > > That sort of says it all, far as I'm concerned. > > keith whaley > > >
Re: Lens resolution
> > But in ordinary 35mm photographic applications 50-60 lines per millimetre on > the film is great ... and good enough for nice big prints; which will not > show more than about a tenth of this anyway. A slight exaggeration. An 8x12 print from a 35mm original is about 8x enlargement. So if the image on the film is 60 lines/line pairs per mm, and we don't lose too much in the printing process, we could get theoretically something approaching 7.5 lines/mm, or almost 200 lines/inch. We *do* lose something in the printing, of course. But I've got 8x10 prints where it is quite easy to see detail at better than 3 lines/mm - closer to 50% than 10%, even assuming I managed to get 60 lines/mm onto the film.
RE: Lens resolution
Logically, because for one line to exist, it must have a background. If it is thought of as a black line then it has a white background. If it is thought of as a white line then it has a black background. By saying that the "pair" is a black line and a white line, then it is not possible to draw one line pair! No one draws a black line on a white piece of paper and claims it's a line pair! No one draws two black lines parallel together on a sheet of paper and claims it's four lines! No one draws 100 black lines parallel together on a sheet of paper and claims it's 200 lines! I'm starting to become convinced that the idea of "line pairs per mm" started as the result of some anal retentive who, for the sake of argument alone, claimed that one could think of the resolution target as white lines on a black background just as well as black lines on a white background (true enough). Either he or others decided that it was somehow "more scientific, more intellectual or whatever" to start calling both the black area and the white area as lines. To me, this leap is nonsense. I am quickly beginning to believe that "line pairs per millimeter" is nothing more than a pseudo intellectual attempt to sound more knowledgeable about the topic, and (in fact) is really the same as lines per millimeter. Indeed, a 10^100 search of the web shows that the terms are often used interchangeably and refer to the same number. To me, this means that lp/mm = l/mm, and that nonsense speak has crawled into our photo jargon even at the highest levels just as it has into the jargon of my engineering profession. The following link discusses the best resolution one can theoretically achieve with any lens given it's f/stop: http://www.zeiss.de/de/photo/home_e.nsf/0/73d528c09b620a11c125697700548cd6?O penDocument Note that for 200 line pairs per millimeter, they give the rounded approximation of f/8 for a white light spectrum of even energy distribution. This corresponds very well with my earlier calculated estimate of f/7.3 for green (monochromatic) light which was relative to lines (on a background) per millimeter. Whether you say "lines per millimeter" or "line pairs per millimeter" the number is the same. Other noteworthy excerpts from this Zeiss article: "Today's high quality color films do reach resolutions in the region of 140 line pairs per millimeter with Kodak Ektar 25 leading the field at 200! The full resolution potential of these films cannot be utilized with existing depth-of-field concepts nor f-settings of f/11 and beyond. On the other hand all real lenses on the market today are limited not only by diffraction, but by lens errors also. Some of them quite heavily." > From: J. C. O'Connell [mailto:[EMAIL PROTECTED] > > One black line and one white line is a "PAIR" > of lines to me. Why would you need 4 lines > to make up a pair? >
RE: Lens resolution
contrast and resolution are intertwined, you cant specify a resolution without also specifying the loss of contrast at the resolving limit. JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Dr E D F Williams [mailto:[EMAIL PROTECTED] Sent: Monday, September 15, 2003 2:20 PM To: [EMAIL PROTECTED] Subject: Re: Lens resolution Correct. 'Lines per Millimetre' is the way Kodak described the resolution of their plates. Those we used for high resolution work resolved about 1200 lines per millimetre. The Holographic plates were much better and more expensive. Now that I've thought about this a little our Kern Switars may have done about 450 lpm. But in ordinary 35mm photographic applications 50-60 lines per millimetre on the film is great ... and good enough for nice big prints; which will not show more than about a tenth of this anyway. But contrast is more important than resolution and without wanting to start a whole new ball rolling, very high resolution pictures with low contrast are terrible. In transmission light microscopy one needs some of each and for that a very carefully adjusted light source, according to 'Köhler's' principle, is required. But for high resolution one needs high resolution film. I think T-Max 100 should resolve about a hundred lpm with care and proper processing. And it has a range of about 8 stops which makes it, and Technical Pan, Kodak's best offerings for B&W photomicrography on 35mm. Don ___ Dr E D F Williams http://personal.inet.fi/cool/don.williams Author's Web Site and Photo Gallery Updated: July 31, 2003 - Original Message - From: "John Francis" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, September 15, 2003 8:31 PM Subject: Re: Lens resolution > > > > One black line and one white line is a "PAIR" > > of lines to me. Why would you need 4 lines > > to make up a pair? > > You don't. It's line *pairs* per mm if you count both the black > and the white line. If you only count the black lines (treating > the white as just the background) you get lines per mm. > > In other words: > > 100 line *pairs* per mmm is 100 black lines and 100 white lines. > > 100 lines per mm is 100 black lines (on a white background), or > alternatively 100 white lines (on a black background). > > They all describe the same resolution pattern. The terminology > using line pairs is technically more correct, but the other usage > is widespread and is a closer analogue to the measurements used in > diffraction gratings, which generally talk about rulings per mm. >
Re: Lens resolution
Correct. 'Lines per Millimetre' is the way Kodak described the resolution of their plates. Those we used for high resolution work resolved about 1200 lines per millimetre. The Holographic plates were much better and more expensive. Now that I've thought about this a little our Kern Switars may have done about 450 lpm. But in ordinary 35mm photographic applications 50-60 lines per millimetre on the film is great ... and good enough for nice big prints; which will not show more than about a tenth of this anyway. But contrast is more important than resolution and without wanting to start a whole new ball rolling, very high resolution pictures with low contrast are terrible. In transmission light microscopy one needs some of each and for that a very carefully adjusted light source, according to 'Köhler's' principle, is required. But for high resolution one needs high resolution film. I think T-Max 100 should resolve about a hundred lpm with care and proper processing. And it has a range of about 8 stops which makes it, and Technical Pan, Kodak's best offerings for B&W photomicrography on 35mm. Don ___ Dr E D F Williams http://personal.inet.fi/cool/don.williams Author's Web Site and Photo Gallery Updated: July 31, 2003 - Original Message - From: "John Francis" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, September 15, 2003 8:31 PM Subject: Re: Lens resolution > > > > One black line and one white line is a "PAIR" > > of lines to me. Why would you need 4 lines > > to make up a pair? > > You don't. It's line *pairs* per mm if you count both the black > and the white line. If you only count the black lines (treating > the white as just the background) you get lines per mm. > > In other words: > > 100 line *pairs* per mmm is 100 black lines and 100 white lines. > > 100 lines per mm is 100 black lines (on a white background), or > alternatively 100 white lines (on a black background). > > They all describe the same resolution pattern. The terminology > using line pairs is technically more correct, but the other usage > is widespread and is a closer analogue to the measurements used in > diffraction gratings, which generally talk about rulings per mm. >
Re: Lens resolution
"John Francis" <[EMAIL PROTECTED]> wrote: >> >> One black line and one white line is a "PAIR" >> of lines to me. Why would you need 4 lines >> to make up a pair? > >You don't. It's line *pairs* per mm if you count both the black >and the white line. If you only count the black lines (treating >the white as just the background) you get lines per mm. That was my understanding. -- Mark Roberts Photography and writing www.robertstech.com
Re: Lens resolution
> > One black line and one white line is a "PAIR" > of lines to me. Why would you need 4 lines > to make up a pair? You don't. It's line *pairs* per mm if you count both the black and the white line. If you only count the black lines (treating the white as just the background) you get lines per mm. In other words: 100 line *pairs* per mmm is 100 black lines and 100 white lines. 100 lines per mm is 100 black lines (on a white background), or alternatively 100 white lines (on a black background). They all describe the same resolution pattern. The terminology using line pairs is technically more correct, but the other usage is widespread and is a closer analogue to the measurements used in diffraction gratings, which generally talk about rulings per mm.
RE: Lens resolution
One black line and one white line is a "PAIR" of lines to me. Why would you need 4 lines to make up a pair? J C O J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Keith Whaley [mailto:[EMAIL PROTECTED] Sent: Monday, September 15, 2003 11:17 AM To: [EMAIL PROTECTED] Subject: Re: Lens resolution Hi Mark, One of anything cannot be a pair. You have lines and spaces to work with. A line "pair" cannot be construed to be one line & one space. It's got to be two lines & two spaces. One of each does not constitute a pair; two of each does. So it seems to me. keith Mark Roberts wrote: > > "Bob Blakely" <[EMAIL PROTECTED]> wrote: > > >The wording, line pairs per mm, implies two black lines and two white lines > >in as much as "pairs" is plural and also because there are many more than > >two lines in the target. This would mean that line pairs per mm would be > >half of lines per mm. > > Hmm. At least one source I've seen regarded one black line and one white > line as a "pair". > > -- > Mark Roberts > Photography and writing > www.robertstech.com
Re: Lens resolution
Well, not this source. To me, a line is a construction with the background necessary for it to exist as a line. A black line only exists on it's accompanying white background. A white line only exists on it's accompanying black background. Generally, when folks talk about lines, They are talking about the marks made on top of a background. When looking at resolution mathematically in order to determine resolution, one talks about how close one can bring one airy disk to another and still discern that there are actually two airy disks and not one oblong image. When a diffraction grating is used, one does not refer to the space between the grating lines, they are understood to exist. One only refers to the number of lines (scores or whatever) per unit measure. Of course there may be some in photography prefer to use conventions or references different from other folks who need to refer to resolution, such as astronomers, radar engineers, etc. and desire to view white and black space as separate lines. You can understand why other folks in other disciplines don't. It is easy to determine what is actually being measured. Get an Air Force resolution measurement target, count the number of lines per mm on a specific part of the target. Do the geometry per the target use instructions to determine the number of lines per mm at the film plane. Regards, Bob... "Do not suppose that abuses are eliminated by destroying the object which is abused. Men can go wrong with wine and women. Shall we then prohibit and abolish women?" -Martin Luther From: "Mark Roberts" <[EMAIL PROTECTED]> > "Bob Blakely" <[EMAIL PROTECTED]> wrote: > > >The wording, line pairs per mm, implies two black lines and two white lines > >in as much as "pairs" is plural and also because there are many more than > >two lines in the target. This would mean that line pairs per mm would be > >half of lines per mm. > > Hmm. At least one source I've seen regarded one black line and one white > line as a "pair".
Re: Lens resolution
Mark wrote: MR> Hmm. At least one source I've seen regarded one black line and one white MR> line as a "pair". I concur. A line pair per mm is just that, a black and a white line. In digital terms it corresponds to 2 pixels. Servus, Alin
Re: Lens resolution
Hi Mark, One of anything cannot be a pair. You have lines and spaces to work with. A line "pair" cannot be construed to be one line & one space. It's got to be two lines & two spaces. One of each does not constitute a pair; two of each does. So it seems to me. keith Mark Roberts wrote: > > "Bob Blakely" <[EMAIL PROTECTED]> wrote: > > >The wording, line pairs per mm, implies two black lines and two white lines > >in as much as "pairs" is plural and also because there are many more than > >two lines in the target. This would mean that line pairs per mm would be > >half of lines per mm. > > Hmm. At least one source I've seen regarded one black line and one white > line as a "pair". > > -- > Mark Roberts > Photography and writing > www.robertstech.com
Re: Lens resolution
I follow that...makes sense. Thanks. keith Bob Blakely wrote: > > The wording, line pairs per mm, implies two black lines and two white lines > in as much as "pairs" is plural and also because there are many more than > two lines in the target. This would mean that line pairs per mm would be > half of lines per mm. > > Regards, > Bob... > > From: "Keith Whaley" <[EMAIL PROTECTED]> > > > Let me get some of my confusion straightened out, before I go into > > overload! > > > > Some sources I've read and some posts I've read here quote line pairs > > per mm, while others speak of lines per mm as resolution values. > > I have observed some posters using one value when they meant the other, > > and I doubt they intend to. > > I think we ought to stick with one system of measurement, for clarity, > > and I'm intending to start with me!
Re: Lens resolution
"Bob Blakely" <[EMAIL PROTECTED]> wrote: >The wording, line pairs per mm, implies two black lines and two white lines >in as much as "pairs" is plural and also because there are many more than >two lines in the target. This would mean that line pairs per mm would be >half of lines per mm. Hmm. At least one source I've seen regarded one black line and one white line as a "pair". -- Mark Roberts Photography and writing www.robertstech.com
Re: Lens resolution
The wording, line pairs per mm, implies two black lines and two white lines in as much as "pairs" is plural and also because there are many more than two lines in the target. This would mean that line pairs per mm would be half of lines per mm. Regards, Bob... "Do not suppose that abuses are eliminated by destroying the object which is abused. Men can go wrong with wine and women. Shall we then prohibit and abolish women?" -Martin Luther From: "Keith Whaley" <[EMAIL PROTECTED]> > Let me get some of my confusion straightened out, before I go into > overload! > > Some sources I've read and some posts I've read here quote line pairs > per mm, while others speak of lines per mm as resolution values. > I have observed some posters using one value when they meant the other, > and I doubt they intend to. > I think we ought to stick with one system of measurement, for clarity, > and I'm intending to start with me!
Re: Lens resolution
Let me get some of my confusion straightened out, before I go into overload! Some sources I've read and some posts I've read here quote line pairs per mm, while others speak of lines per mm as resolution values. I have observed some posters using one value when they meant the other, and I doubt they intend to. I think we ought to stick with one system of measurement, for clarity, and I'm intending to start with me! I assume a resolution test target would have varying values of line widths and spacing, for evaluation purposes, but for illustration, can I assume a "line pair" is defined as two black lines of equal width separated by white or grey space the same width as the lines? For instance, if I were to specify a .01mm line width, a line pair would be two .01mm black lines, with a white space of .01mm width separating them. The "pair" would then have an .03mm overall width. In attempting to equate this to lines per mm values, I will assume the width of one line, plus a space of equal width as being a 'unit' and however many units fit into a 1.0 mm space is the "lines per mm" value. That being so, given the same line widths in each case, for the same resolution capability one would have double the "lines per mm" value than "line pairs per mm." Agreed? In other words, a lens with a resolving power of 25 line pairs per mm can also be said to be able to resolve 50 lines per mm. Same actual resolution capability, different units. Is one of them any industry-accepted "standard?" keith whaley [EMAIL PROTECTED] wrote: > > Even with a perfect lens, there's no way you can get close to 100 lp/mm at aperture > 22. > > DagT > > > > > Fra: "J. C. O'Connell" <[EMAIL PROTECTED]> > > NOT TRUE, > > > > Even the best 35mm film is only about 200 lp/mm. > > > > Even using an excellent lens of 200 lp/mm results > > in a film/lens combination of only 100 lp/mm. > > > > The film DOES affect the result, even the best films > > JCO
RE: RE: Lens resolution
I did, I said that: "With a good film, the lens sets the limit, especially when using small apertures." Others have given more detailed explanations regarding diffraction limits and imperfect lenses. Yes, there are some great lenses out there, but you only get 200 lp/mm at the optical centre of perfect lenses at large apertures. This is not what you usually have in your bag, and you don't use a perfect tripod you probably wouldn't obtain it any way. DagT > Fra: "J. C. O'Connell" <[EMAIL PROTECTED]> > who said we were talking about f22? > > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Monday, September 15, 2003 3:52 AM > To: [EMAIL PROTECTED] > Subject: Re: RE: Lens resolution > > > Even with a perfect lens, there's no way you can get close to 100 lp/mm at > aperture 22. > > DagT > > > Fra: "J. C. O'Connell" <[EMAIL PROTECTED]> > > NOT TRUE, > > > > Even the best 35mm film is only about 200 lp/mm. > > > > Even using an excellent lens of 200 lp/mm results > > in a film/lens combination of only 100 lp/mm. > > > > The film DOES affect the result, even the best films > > JCO > > > > -Original Message- > > From: Dag T [mailto:[EMAIL PROTECTED] > > <> > > > > With a good film, the lens sets the limit, especially when using small > > apertures. > > > > DagT > > > > > >
Re: Lens resolution
- Original Message - From: "J. C. O'Connell" Subject: RE: Lens resolution > There are lenses capable of several hundred lp/mm but this is > measured with an aerial image and 1000:1 contrast target. > You also need to use a single wavelength of light and special > fast lenses (stopping down reduces resolution). This bears no resemblance to real world photography. > > The film with 200lp/mm resolution is TMAX 100, technical pan is even > better. T-Max 100 is 63 l/mm (not lppm) at what is considered real world subject contrast. I know you are correct about Tech Pan, but the numbers are hard to get as Kodak doesn't like to publish them. > > I have heard of a few lens/film combinations reaching 100 lp/mm > so it is possible. I think it was some of the 90/100mm macros > on tech pan. It's possible, I just don't think it likely outside of a laboratory setting. > > Of course the easist solution to get true high resolution photographs > is to use LARGE FORMAT. With 35mm you are in an endless pursuit > of mediocrity... Agreed. William Robb
RE: Lens resolution
"J. C. O'Connell" wrote: > > NOT TRUE, > > Even the best 35mm film is only about 200 lp/mm. > > Even using an excellent lens of 200 lp/mm results > in a film/lens combination of only 100 lp/mm. Huh? Two times excellent equals only 1/2 of excellent? In the first place, where, pray tell, would you GET this so-called "excellent lens," capable of resolving 200 line pairs per mm? I know of no consumer level lens capable of that level of resolution. Understand, JC, I'm not calling you out. I really want to know! > The film DOES affect the result, even the best films > JCO Of course, you're right. I agree, but the question remains. If you can find a film that consistently delivers a resolution of 200 lp/mm, what are you going to use to impress an image on a frame or two? No, I mean a lens available to the average photographer? Even a rich professional photographer? keith whaley The only problem with this is that the only way to get that kind of resolution off either a film or lens is to photograph a resolution target. In the real world, the best lenses and film are closer to 50 lp/mm. I think right now, good film and good lenses are pretty closely matched resolution wise, film may actually have an edge, so to speak. William Robb 8 There are lenses capable of several hundred lp/mm but this is measured with an aerial image and 1000:1 contrast target. You also need to use a single wavelength of light and special fast lenses (stopping down reduces resolution). The film with 200lp/mm resolution is TMAX 100, technical pan is even better. I have heard of a few lens/film combinations reaching 100 lp/mm so it is possible. I think it was some of the 90/100mm macros on tech pan. Of course the easist solution to get true high resolution photographs is to use LARGE FORMAT. With 35mm you are in an endless pursuit of mediocrity... JCO
Re: Lens resolution
On 14 Sep 2003 at 16:58, Keith Whaley wrote: > Huh? Two times excellent equals only 1/2 of excellent? > > In the first place, where, pray tell, would you GET this so-called > "excellent lens," capable of resolving 200 line pairs per mm? > I know of no consumer level lens capable of that level of resolution. > Understand, JC, I'm not calling you out. I really want to know! Check the following site: http://www.hevanet.com/cperez/index.html Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
Re: Lens resolution
- Original Message - From: "J. C. O'Connell" Subject: RE: Lens resolution > NOT TRUE, > > Even the best 35mm film is only about 200 lp/mm. > > Even using an excellent lens of 200 lp/mm results > in a film/lens combination of only 100 lp/mm. > The only problem with this is that the only way to get that kind of resolution off either a film or lens is to photograph a resolution target. In the real world, the best lenses and film are closer to 50 lp/mm. I think right now, good film and good lenses are pretty closely matched resolution wise, film may actually have an edge, so to speak. William Robb
Re: Lens resolution
"J. C. O'Connell" wrote: > > NOT TRUE, > > Even the best 35mm film is only about 200 lp/mm. > > Even using an excellent lens of 200 lp/mm results > in a film/lens combination of only 100 lp/mm. Huh? Two times excellent equals only 1/2 of excellent? In the first place, where, pray tell, would you GET this so-called "excellent lens," capable of resolving 200 line pairs per mm? I know of no consumer level lens capable of that level of resolution. Understand, JC, I'm not calling you out. I really want to know! > The film DOES affect the result, even the best films > JCO Of course, you're right. I agree, but the question remains. If you can find a film that consistently delivers a resolution of 200 lp/mm, what are you going to use to impress an image on a frame or two? No, I mean a lens available to the average photographer? Even a rich professional photographer? keith whaley
RE: Lens resolution
NOT TRUE, Even the best 35mm film is only about 200 lp/mm. Even using an excellent lens of 200 lp/mm results in a film/lens combination of only 100 lp/mm. The film DOES affect the result, even the best films JCO J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com -Original Message- From: Dag T [mailto:[EMAIL PROTECTED] Sent: Sunday, September 14, 2003 4:23 PM To: [EMAIL PROTECTED] Subject: Re: Lens resolution På søndag, 14. september 2003, kl. 18:49, skrev Anders Hultman: > Bob Blakely: > >>> I've seen people here talk about the resolution of lenses. I fully >>> understand the physics behind resolution of both digital image >>> sensors and film, but what really is resolution when talking about >>> lenses? >> >> Lens resolution is defined as the number of resolution target lines >> per >> millimeter that can be discerned in the film. Discerned means that the >> individual lines from the target can be seen, however slight and >> fuzzy. >> Where the lines cannot be discerned, a (theoretically) 50% gray is >> observed. >> The lines are black and the spaces between parallel lines are white >> and of >> the same width as the lines. > > To me, this sounds like this would be a property of the film, not a > property of the lens? I mean, with higher definition film, a film with > finer grain or whatever, it would be possible to show more detail, > wouldn't it? > > Or is it really the lens itself that blurs the lines? > With a good film, the lens sets the limit, especially when using small apertures. DagT
Re: Lens resolution
På søndag, 14. september 2003, kl. 18:49, skrev Anders Hultman: Bob Blakely: I've seen people here talk about the resolution of lenses. I fully understand the physics behind resolution of both digital image sensors and film, but what really is resolution when talking about lenses? Lens resolution is defined as the number of resolution target lines per millimeter that can be discerned in the film. Discerned means that the individual lines from the target can be seen, however slight and fuzzy. Where the lines cannot be discerned, a (theoretically) 50% gray is observed. The lines are black and the spaces between parallel lines are white and of the same width as the lines. To me, this sounds like this would be a property of the film, not a property of the lens? I mean, with higher definition film, a film with finer grain or whatever, it would be possible to show more detail, wouldn't it? Or is it really the lens itself that blurs the lines? With a good film, the lens sets the limit, especially when using small apertures. DagT
Re: Lens resolution
It is the old 1 over a + b + c type thing. The overall resolutions is going to be less than the lowest resolution of all the things imvolved. Lens, film, chemistry, paper, scanner, whatever. It can not be any better than the worse thing in the line up. --- Anders Hultman wrote: Bob Blakely: I've seen people here talk about the resolution of lenses. I fully understand the physics behind resolution of both digital image sensors and film, but what really is resolution when talking about lenses? Lens resolution is defined as the number of resolution target lines per millimeter that can be discerned in the film. Discerned means that the individual lines from the target can be seen, however slight and fuzzy. Where the lines cannot be discerned, a (theoretically) 50% gray is observed. The lines are black and the spaces between parallel lines are white and of the same width as the lines. To me, this sounds like this would be a property of the film, not a property of the lens? I mean, with higher definition film, a film with finer grain or whatever, it would be possible to show more detail, wouldn't it? Or is it really the lens itself that blurs the lines? anders - http://anders.hultman.nu/ -- --graywolf http://graywolfphoto.com
Re: Lens resolution
Lens resolution is defined as the number of resolution target lines per millimeter that can be discerned in the film. Discerned means that the individual lines from the target can be seen, however slight and fuzzy. Where the lines cannot be discerned, a (theoretically) 50% gray is observed. The lines are black and the spaces between parallel lines are white and of the same width as the lines. The resolution target is of a standard size and provides lines of various spacing and at various places in the field of view and in various orientations. The target is properly filled by adjusting the camera to subject distance. The math of this geometry is used to translate target lines per millimeter to lines per mm at the film plane. In practice, the measurement is made using high power loupes examining (properly exposed and developed) high resolution, high contrast film. There is no hard standard for the film used and different labs use different films and different targets have "blacker" blacks" and "whiter" whites. There is an Air Force standard target which is often used, but often folks use replicas of this target. This means that the observed resolution varies from lab to lab, person to person. Therefore, do not compare the results of one lab with another, or one persons measurement with another. Regards, Bob... "Do not suppose that abuses are eliminated by destroying the object which is abused. Men can go wrong with wine and women. Shall we then prohibit and abolish women?" -Martin Luther From: "Anders Hultman" <[EMAIL PROTECTED]> > I've seen people here talk about the resolution of lenses. I fully > understand the physics behind resolution of both digital image > sensors and film, but what really is resolution when talking about > lenses?
Lens resolution
I've seen people here talk about the resolution of lenses. I fully understand the physics behind resolution of both digital image sensors and film, but what really is resolution when talking about lenses? anders - http://anders.hultman.nu/
Re: The DSLR, 35mm lens resolution, and festive good wishes
Cameron wrote: > Given that 35mm lenses are the best there are, I don't think they are. All things equal, smaller format lenses will be better. I've heard that the Minox lens is way better than any 35mm system lens. No idea if it is true... Pål
Re: The DSLR, 35mm lens resolution, and festive good wishes
Cameron: > It is too bad that at this point, it is only a dream and conjecture. > February, you say, Paal. I sure hope so; it has been a long wait. Don't stick the full frame Pentax DSLR rumor on me. Pentax will show an APS sized sensor DSLR in spring. Pål
The DSLR, 35mm lens resolution, and festive good wishes
Given that 35mm lenses are the best there are, and that Pentax may eventually have a real high end full frame 35mm DSLR, with the resolution at or greater than the current offerings from other manufacturers, I can only dream about the kind of quality we will get when shooting with some of the best of Pentax glass. I recently downloaded a large jpeg shot on the current Canon 11 meg (I think) camera, and the clarity, sharpness, and detail makes it look like shots from larger formats. Imagine the stuff we are going to get with the mighty FA* series and limited lenses; the 85mm FA*, which I am gradually growing to adore even more than the 24mm FA* f=2, is going to yield portraits of uncompromising clarity, detail, resolution, and contrast, and to have full control in photoshop on a Mac, with fire-wire download times, and prints from an Epson 1270 or equivalent on premium glossy, rivalling that of Cibachrome...it will truly be photographic heaven. Imagine the resolution we will get with landscapes from the 24mm, the birdy shots from the 300's, the macros with the 50, the 100, and the mighty FA* 200mm macro (I'm saving my pennies for that one). It is too bad that at this point, it is only a dream and conjecture. February, you say, Paal. I sure hope so; it has been a long wait. On a more festive note, Merry Christmas, Happy Hannukah (pardon my spelling), and great good wishes, peace, and happiness to all, whatever your beliefs may be. This is a beautiful world we live in, the one which we share the joy of documenting in our photographs. Maybe some great photograph, one day, will pull the world together, and we can stop all this petty bickering and work together, finally realizing our great human potential; when all is said and done, there is only one race, the Human Race. Let us all think, wish, pray, visualize, and work towards peace in this troubled world this holiday season. Love to all. Cameron R. Hood, Pentaxian
Re: Lens resolution: 35mm vs. medium-format
Very cogent description, it's obvious why Mike can make a living with his pen, (ok, word processor). At 10:05 AM 12/15/2002 -0600, you wrote: > All you have to do is take a look at the published MTFs for 35 mm lenses and > compare them with those for Medium Format Again, Don and Pal are correct here. Look at any measure of resolving power you please--visual lp/mm, MTF, whatever--the smaller the image circle, the shorter the focal length for the same angle of view, the brighter the lens, the higher the potential resolution. There isn't a single medium format lens that can resolve as much on film as the best 35mm lens. Where medium format wins is by the measure Greywolf was referencing in his part of the discussion--final print magnification as opposed to on-film magnification. With normal-speed pictorial films (i.e., 100-400 ISO), the limits of enlargement are about 8-12x (depending no so much on the granularity of the film as upon the quality of the enlarging lens and the technique of the printer--I'll give you a clue, if you don't know the optimum magnification and the optimum aperture of your enlarging lens off the top of your head, you're better off not going to 12x ). An 8x enlargement from 35mm is 12x8 inches. The same 8x enlargement from a Hasselblad or Rollei negative is eighteen and a half inches square. You can crop a square medium-format negative and enlarge it to 12x8 inches and you're still only at about a 5x enlargement. What this means IN REAL-WORLD TERMS is that a 12x8-inch enlargement from a 2 1/4 negative requires less skill and less exacting technique from the printer, allows for some cropping, allows for the use of a faster film, and STILL will give better resolution in the print. Nothing to be sneezed at. And if what you want to end up with is an 18x12-inch print, however, that's a 12x enlargement from a 35mm negative and, in practical terms, you are working at the limits of 35mm--your equipment, materials, and technique had all better be top-notch to achieve a better-than-acceptable result. But you're only at the bottom limit of the enlargability of a 2 1/4 neg. In fact, subjective evaluation tests show that this is pretty much the story with competing formats. If both formats are well under the lower enlargability index of 8x, there isn't a whole lot to choose. By the upper 12x limit of the smaller format, the larger format is beginning to pull away decisively. At larger sizes, no amount of technique can "rescue" the smaller format. The big headache for manufacturers (as I think the "Big Five" found out to their dismay with APS) is that a format cannot be engineered for the "average" enlargement--because, in the real world, what people like to do is to have MOST of their enlargements at a certain size, but then a FEW SELECTED images they like to be able to enlarge to a significantly greater size. That is, the APS shooter is happy with 3R prints most of the time, but occasonally wants an 8x10; The 35mm shooter is happy with 4x6 or 6x9 most of the time, but SOMETIMES wants an 11x14. So format choice is not only dependent on the comfort level it allows a fine printer at the average size of enlargement, but it is also a matter of the LARGEST size he or she is ever likely to print. Incidentally, in our subjective evaluation tests, the ideal format turned out to be 6x7cm. In 11x14 enlargements, photographers could tell, but visually sensitive laypeople COULD NOT TELL, the difference between 6x7 and 4x5. Yet 6x7 DECISIVELY bettered 35mm at every size above about 6x9, according to all viewers, and by 16x20 there was not contest at all--100% of viewers preferred 6x7. Do note, however, that lens and film resolution, enlargability, print quality, and all these interlinking qualities are NOT simply a matter of mathematics and measurements. They are also highly dependent on the skill and technique of the photographer/printer and the visual acuity and "sensitivity to photo artifacts" of the viewer. Photographers can more readily tell the differences between formats because they know the clues to look for. Ordinary viewers don't see the differences as easily. All these things have to be taken into account in this argument. --Mike "At least they're not talking about my eyes any more. I was starting to get self-conscious." (Rocky Raccoon) * * * Find out about Mike Johnston's unique photography newsletter, "The 37th Frame," at http://www.37thframe.com.
Re[2]: Lens resolution: 35mm vs. medium-format
Vic, I'm not sure that any of us on the list that have/use MF or LF think that it is ONLY way to go. I still have my 35mm gear and use it. Just not that often. When the situation calls for it, that is what I use. My Coolpix 990 digicam also gets a fair amount of use for snapshots or instant needed images. To answer your other points - I make lots of 8X10's and some larger 11X14, 16X20 and 20X24. Beyond 8X10 is mostly for commercial stuff. I tend not to hang my own work - prefer book/portfolio presentation. For that, I use 8X10's. I can see a difference in prints at 5X7 and more so at 8X10 or greater. A good example of 5X7 was shooting a concert with Delta 3200. The 5X7 blowups from the 67 negs were almost grainless looking. The 35mm stuff was painfully worse looking. Now, generally I try to shoot 100 speed (Reala, Optima II) type films on 35mm, but differences can still be seen. I tend to go with the philosophy of use the biggest negative you can in a given situation. The situations become very obvious. Longer telephoto stuff, quiet stuff, low res shots (for web or slide shows) where I will be taking lots and lots (need quantity to tell story of the even), some macro, size & weight impacted shoots all push me to 35mm. I am happy to have both systems and be able to choose when I need to. Not sure I understand your last statement "You can be shooting with the best medium format or large format camera in the world but it doesn't mean your pictures are any better". If you mean someone else with a smaller format can take a better picture than you, I would agree because content, composition, etc are all important factors in the final image. But the same photographer, shooting the same picture with small and medium/large format will have a technically more usable image due to the amount of detail captured and the lack of blowup needed for enlargements. I do believe having a fun, usable camera is important as the process of creating images is part/most of the enjoyment for me. I haven't cared for the TLR or waist level square box style camera that is prevalent in the MF world. Both offerings from Pentax handled in a manner that I found enjoyable. I can use my 67II just about like I was using my MZ-S. My niece (working wedding photographer), on the other hand, almost never uses her 'Blad because she doesn't care for how it handles. All the working pros in her area told her that is what she should use. Bruce Sunday, December 15, 2002, 12:50:53 PM, you wrote: Pac> Very good points Mike. Well said. Agree wholeheartedly. Pac> Let me ask these questions: How many photographers on this list who think Pac> that MF or LF is the ONLY way to go really blow up their images beyond 8X10 Pac> and 11X14 on a regular basis? Pac> And of those who do, how many are doing it commercially and how many are Pac> doing it to hang on their own walls? Pac> And what type of photography do they do...static, action, pictorial ... Pac> These are (in my opinion) valid questions. Because it's really the type of Pac> photography you do and the end use of your photography that dictates the Pac> appropriate type of system. You can be shooting with the best medium format Pac> or large format camera in the world but it doesn't mean your pictures are any Pac> better Pac> Vic Pac> PS I have medium format Yashica and larger format Crown Graphic and never use Pac> them, ever
Re: Lens resolution: 35mm vs. medium-format
- Original Message - From: <[EMAIL PROTECTED]> Subject: Re: Lens resolution: 35mm vs. medium-format > Very good points Mike. Well said. Agree wholeheartedly. > Let me ask these questions: How many photographers on this list who think > that MF or LF is the ONLY way to go really blow up their images beyond 8X10 > and 11X14 on a regular basis? Obviously, I think so. > And of those who do, how many are doing it commercially and how many are > doing it to hang on their own walls? Both. > And what type of photography do they do...static, action, pictorial ... Product, weddings, portraiture, landscape/pictorial, some glamour. If I can do it on the larger film I will. > These are (in my opinion) valid questions. Because it's really the type of > photography you do and the end use of your photography that dictates the > appropriate type of system. You can be shooting with the best medium format > or large format camera in the world but it doesn't mean your pictures are any > better Define better. William Robb
Re: Picture Resolution & size (Was: Lens resolution: 35mm vs. medium-format)
On 15 Dec 2002 at 15:04, Bruce Dayton wrote: > Doug, > > Why do you say "intuitively"? I don't see it that way. It would > still seem to come down to quality of equipment. Are you assuming > that digital scanners are better resolution that the optical systems? No Doug, but.. Once an image is in the digital domain the aberrations introduced in transformations are predictable and controllable i.e. they are a function of the algorithm used to facilitate the digital enlargement. No optical system like aberrations are introduced through digital scaling. Also most of the new scanners seem to incorporate some pretty advanced optics and they need to be to truly record resolutions of 4000dpi and above from film. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications.html
Re: Picture Resolution & size (Was: Lens resolution: 35mm vs. medium-format)
Doug, Why do you say "intuitively"? I don't see it that way. It would still seem to come down to quality of equipment. Are you assuming that digital scanners are better resolution that the optical systems? Please explain. Thanks, Bruce Sunday, December 15, 2002, 8:40:23 AM, you wrote: DF> On Sun, 15 Dec 2002 10:05:24 -0600, Mike Johnston wrote: >> [...] limits of enlargement are about 8-12x (depending no[t] so >> much on the granularity of the film as upon the quality of the >> enlarging lens and the technique of the printer-- [...] DF> So where are we when we convert the "optically enlarge, optically DF> print" steps of the process to "digitally enlarge, digitally print"? DF> Intuitively, it would seem that the potential for greater DF> magnifications would be increased. DF> TTYL, DougF KG4LMZ
Picture Resolution & size (Was: Lens resolution: 35mm vs. medium-format)
Message text written by INTERNET:[EMAIL PROTECTED] >So where are we when we convert the "optically enlarge, optically print" steps of the process to "digitally enlarge, digitally print"? Intuitively, it would seem that the potential for greater magnifications would be increased. TTYL, DougF KG4LMZ< i think we need better film and lenses then. 4000 dpi is already picking up clumping from grain as most of its fine detail. several vendors make 4000dpi medium format scanners that can handle a 6x9cm sheet of film. i know on Provia 100F, my scans can easily pick out chromatic aberration at the corners from my FA 24-90 and my FA* 24mm at my usual working apertures of f8 and smaller. there is a slight amount visible as well on my FA* 80-200mm. Herb
Re: Lens resolution: 35mm vs. medium-format
Popular Photography has some MF lens tests on line. One is http://www.popphoto.com/pdfs/2002/1002/lenstests/Mamiya.pdf This test reports resolution (not SQF). Pop Photog if nothing else has been pretty consistent in their resolution tests over the years. The Mamiya prime has some pretty good numbers, even for a 35mm format lens. BR From: =?iso-8859-1?Q?P=E5l_Jensen?= <[EMAIL PROTECTED]> And don't think you can use numbers in this way. If such numbers are to be compared they should be done by the same lab and preferably by the same operator.
Re: Lens resolution: 35mm vs. medium-format
It must also be remembered that without a "perfect" lens you will not achieve the max resolution of the film. System resolution is calculated like adding resistors in parallel. So if you have film that can resolve 100 lp/mm and a lens that can resolve 1000 lp/mm, you get less than 100 lp/mm when that lens and film is combined. I still think that for small prints (5x7 and less) the order of importance is: film, format, lens. For larger prints, film and format swap places. This all assumes things like good tripod, perfect focus and proper exposure/developing. BR From: "T Rittenhouse" <[EMAIL PROTECTED]> My last comment on the subject, I swear. There is not a single lens in the world that can resolve more on film than the film will resolve.
Re: Lens resolution: 35mm vs. medium-format
My last comment on the subject, I swear. There is not a single lens in the world that can resolve more on film than the film will resolve. Ciao, Graywolf http://pages.prodigy.net/graywolfphoto - Original Message - From: "Mike Johnston" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, December 15, 2002 11:05 AM Subject: Lens resolution: 35mm vs. medium-format > > All you have to do is take a look at the published MTFs for 35 mm lenses and > > compare them with those for Medium Format > > > > Again, Don and Pal are correct here. Look at any measure of resolving power > you please--visual lp/mm, MTF, whatever--the smaller the image circle, the > shorter the focal length for the same angle of view, the brighter the lens, > the higher the potential resolution. There isn't a single medium format lens > that can resolve as much on film as the best 35mm lens. > > Where medium format wins is by the measure Greywolf was referencing in his > part of the discussion--final print magnification as opposed to on-film > magnification. With normal-speed pictorial films (i.e., 100-400 ISO), the > limits of enlargement are about 8-12x (depending no so much on the > granularity of the film as upon the quality of the enlarging lens and the > technique of the printer--I'll give you a clue, if you don't know the > optimum magnification and the optimum aperture of your enlarging lens off > the top of your head, you're better off not going to 12x ). > > An 8x enlargement from 35mm is 12x8 inches. The same 8x enlargement from a > Hasselblad or Rollei negative is eighteen and a half inches square. You can > crop a square medium-format negative and enlarge it to 12x8 inches and > you're still only at about a 5x enlargement. What this means IN REAL-WORLD > TERMS is that a 12x8-inch enlargement from a 2 1/4 negative requires less > skill and less exacting technique from the printer, allows for some > cropping, allows for the use of a faster film, and STILL will give better > resolution in the print. Nothing to be sneezed at. > > And if what you want to end up with is an 18x12-inch print, however, that's > a 12x enlargement from a 35mm negative and, in practical terms, you are > working at the limits of 35mm--your equipment, materials, and technique had > all better be top-notch to achieve a better-than-acceptable result. But > you're only at the bottom limit of the enlargability of a 2 1/4 neg. > > In fact, subjective evaluation tests show that this is pretty much the story > with competing formats. If both formats are well under the lower > enlargability index of 8x, there isn't a whole lot to choose. By the upper > 12x limit of the smaller format, the larger format is beginning to pull away > decisively. At larger sizes, no amount of technique can "rescue" the smaller > format. > > The big headache for manufacturers (as I think the "Big Five" found out to > their dismay with APS) is that a format cannot be engineered for the > "average" enlargement--because, in the real world, what people like to do is > to have MOST of their enlargements at a certain size, but then a FEW > SELECTED images they like to be able to enlarge to a significantly greater > size. That is, the APS shooter is happy with 3R prints most of the time, but > occasonally wants an 8x10; The 35mm shooter is happy with 4x6 or 6x9 most of > the time, but SOMETIMES wants an 11x14. So format choice is not only > dependent on the comfort level it allows a fine printer at the average size > of enlargement, but it is also a matter of the LARGEST size he or she is > ever likely to print. > > Incidentally, in our subjective evaluation tests, the ideal format turned > out to be 6x7cm. In 11x14 enlargements, photographers could tell, but > visually sensitive laypeople COULD NOT TELL, the difference between 6x7 and > 4x5. Yet 6x7 DECISIVELY bettered 35mm at every size above about 6x9, > according to all viewers, and by 16x20 there was not contest at all--100% of > viewers preferred 6x7. > > Do note, however, that lens and film resolution, enlargability, print > quality, and all these interlinking qualities are NOT simply a matter of > mathematics and measurements. They are also highly dependent on the skill > and technique of the photographer/printer and the visual acuity and > "sensitivity to photo artifacts" of the viewer. Photographers can more > readily tell the differences between formats because they know the clues to > look for. Ordinary viewers don't see the differences as easily. All these > things have to be taken into account in this argument. > > --Mike > > > > > > > "At least they're not talking about my eyes any more. I was starting to get > self-conscious." (Rocky Raccoon) > > * * * > Find out about Mike Johnston's unique photography newsletter, "The 37th > Frame," at http://www.37thframe.com. >
Re: Picture Resolution & size (Was: Lens resolution: 35mm vs.medium-format)
> So where are we when we convert the "optically enlarge, optically > print" steps of the process to "digitally enlarge, digitally print"? > Intuitively, it would seem that the potential for greater > magnifications would be increased. Possibly. The only reason I'm not willing to say is that I haven't actually done it. --Mike
Re: Picture Resolution & size (Was: Lens resolution: 35mm vs. medium-format)
"Doug Franklin" <[EMAIL PROTECTED]> wrote: >On Sun, 15 Dec 2002 10:05:24 -0600, Mike Johnston wrote: > >> [...] limits of enlargement are about 8-12x (depending no[t] so >> much on the granularity of the film as upon the quality of the >> enlarging lens and the technique of the printer-- [...] > >So where are we when we convert the "optically enlarge, optically >print" steps of the process to "digitally enlarge, digitally print"? >Intuitively, it would seem that the potential for greater >magnifications would be increased. We're just a bit closer to the equivalent of a "theoretically perfect" enlarger and lens. I'd say the potential for greater enlargement is probably increased a little, but not much. -- Mark Roberts Photography and writing www.robertstech.com
