[filmscanners] RE: Dynamic range -- resolution/levels
Roy, > >> All the stuff about number of levels and resolution are > artifacts of the > >> digital process and not part of the DyR concept which existed > way before > >> the word digital was even coined. > > > ... > > I believe the concept of resolution is inherent in the concept > of dynamic > > range. Whether that "works" for you or not, at least for me, > and for many > > other engineers I know, is an important understanding. > > > > Fair enough. But I like to show why I believe that the "concept of > resolution" that results isn't very meaningful. See below. It's SO meaningful, that EVERY PAPER showing how to calculate the number of bits used does it based on dynamic range! How on earth do you explain that? > >> But the SIZE of the range is ONE number -- and it can be mathematically > >> calculated with a subtraction OR with a ratio. In the dynamic range > >> case we always calculate the SIZE of the range with a ratio = max/min. > > > > I see how size can have a merit (which is a relative ratio), > and range, as > > they apply to dynamic range. Size in the fact that the largest > signal is N > > times larger than the smallest...and range in that you can say > "all integer > > values from 1:1 to N:1". BUT...realize that "all integer > values from 1:1 to > > N:1" really denotes a resolution over a particular "range" > too...that you > > have N discrete values. > > Yes, but I never said "integer". In the real-world i.e. analog, there no > reason why any real number couldn't be used. What's wrong with going from > 1:1 to 1.01:1 to 1.02:1 ... Because noise is 1, and you can only measure in increments of noise. In a system that has noise of, say, 1V, you certainly can't measure 1.01V, now can you? > Here's why I have a problem with the "concept of resolution": > > Let me go through a simple example of a (semi-idealized) scanner. > > Here's the basic specs of the scanner: > Density Range: 0D to 3.6D > Bit Depth: 12 bits > Number of levels: 4096 > > A couple of simple observations: > The density range is also 12 photographic stops -- each stop is .3 of > density so 12*.3 = 3.6 > You can chop up the density range into 12 one-stop ranges i.e.: > 0 to .3, .3 to .6, .6 to .9 ... etc to 3.3 to 3.6 > > Photographically and human perception wise each of these one-stop > ranges are equivalent in size. > > So now let's chop the density range into the 4096 levels. The > density range 3.6 divided by 4096 gives a little less than 0.001D > per level. Approximately, 300 levels for each of the 12 one-stop > range. Sounds like a great concept of resolution, doesn't it? > We get a new level every 0.001D change in density -- it sure > looks like a resolution of 0.001D. But that's not how scanners work. They know NOTHING ABOUT density values at all! They only know photons, and how many photons the CCD sees. They see relative values output PURELY AS A VOLTAGE (or possibly current), and that voltage has a range, and has noise. You can only measure as accurately as noise, and as such, noise defines the resolution of that system. > Austin, don't take my word or the web's word for it. Try it yourself. Roy, I've designed film scanners, and have been designing digital imaging systems for over 20 years. I KNOW how they work. All this stuff you wrote is simply irrelevant. What ever the scanner does with the data, or what the data actually represents WRT what the human eye can see, or density values etc. has absolutely NO bearing on capturing the data, and the DYNAMIC RANGE of the input signal, which is what we are talking about. You obviously need to capture the input signal, and what determines at what RESOLUTION you capture it is the dynamic range of the input signal...nothing else. Specifically, the number of bits that you capture the input signal should be such that you resolve down to noise...and you do that by calculating the dynamic range, and, as I've always said, and said, and said...you NEED so many bits to capture a particular dynamic range, period. If it isn't the dynamic range of the input signal to the A/D that determines how many bits you need/should use...what ever you want to call it, then WHAT does? Austin Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] RE: film scanner
Art, thanks for your observation, I if you intent to advocate the SS4000 for lack of ICE3 you couldn't. Perhaps I didn't' get your mood right, but in my original posting I didn't mean to blame Polaroid for absence of these features. Some people do like it some not, it depends. The Polaroid doesn't need to prove itself - it already did it gaining very good reputation. However, I was speaking for me I find ICE and GEM usefulness for my stuff. I cannot boast by sterile environment in which my originals are kept, although strive to tailor them carefully, but there are dust and scratches here and there (seem to be unavoidable) and then ICE really helps saving me a lot of time which I don't have either. Everyone makes his own decisions and choosing particular things doesn't mean unappreciating others. Regards, Alex Z -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Arthur Entlich Sent: Thursday, August 29, 2002 1:22 AM To: [EMAIL PROTECTED] Subject: [filmscanners] Re: film scanner I'll let Howard speak for himself, but I think he stated what he meant. I too have relatively unhanded slides, which do not get scratched with my processor, (finally! ;-)) and also don't have embedded dust or dirt, in general. Also, something Howard didn't mention is that the SS4000 scanners make very good use of the diffused cold cathode lighting, which very much limits the amount of surface defects that appear in the scan. Further, Polaroid supplied a free plug and and separate scratch and dust filter which is pretty effective once you learn how to use it, for the dust that does show. This uses a very different and more effective method of repairing dust and scratches than the Abode dust or scratch filters do. Until recently, anyone could download it and use it on any image (it is done to the scan, not prior to it), but I guess they realized it was something that they wanted to restrict to just Polaroid scanner owners, so you now need a serial number to get it. ICE/IR cleaning is much more of an issue with badly handled film or if you use a Minolta or Nikon scanner, both of which emphasize these surface defects considerably. I know of many users of Polaroid SS4000 and SS4000+ (and the Microtek equivalent) scanners and the vast majority would "like to" have ICE but do not find it a necessity for most applications. Few, if any, have told me they bemoan making the purchase because it lacks ICE. It is truly necessary with Nikon scanners, and a burden to be without on the Minoltas. Of course, with the SS4000 et al. you get that same lighting advantage with black and white film and Kodachrome as well, while ICE does not work at all with real silver halide B&W and some Kodachrome, leaving one with a good deal of spotting work with the Nikon and Minolta scanners. ICE is a great concept. It makes the Nikons, with their LED lighting source, functional, (owners of previous non-ICE Nikon versions told Nikon in no uncertain terms that if they didn't do something about the emphasized dust, dirt and scratches, they wouldn't be selling many more scanners)... It makes production scanners work well and quickly (it is used in many commercial scanners) and it fixes things like fungus and fingerprint damage which are difficult if not impossible to repair. It allows you to be a little less careful in your film cleaning prior to scanning. But, a well designed cold cathode lighting source and considering the cost of the SS4000/+ and its other features (and the black and white film ability without a lot of spotting) make it fine for many without ICE. I don't know how much the ICE features cost in hardware and licensing, but the Minolta Dual II without it costs $600 CAN less in Canada, literally half the price of the Minolta Elite II which has ICE, a slightly better bit depth and firewire... same resolution. People need to decide which features are most important to them, when determining how to get best value from their scanner. GEM is almost unnecessary with the SS4000/+ et al units due to the diffused lighting, (grain is emphasized by grain aliasing in lower res units and by certain lighting designs) and ROC is a separate plug in anyway, if one feels the need for it. Art Alex Zabrovsky wrote: > Howard, you obviously meant you don't miss ROC feature rather then IR > cleaning (ICE) since the originals are all susceptible to dust regardless of > being old or new and can be scratched right > away from the processor. > Otherwise, although really enjoy ICE cleaning and GEM in many cases I also > haven't had an opportunity to try out the ROC not having old faded out stuff > (my photo experience isn't longer then 5 years so far). > > Regards, > Alex Z > > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]]On Behalf Of [EMAIL PROTECTED] > Sent: Wednesday, August 28, 2002 1:10 PM > To: [EMAIL PROTECTED] > Subject: [filmscanners] Re: film scanner > > > < polaroid sprint
[filmscanners] Re: Dynamic range -- resolution/levels
on 9/2/02 12:20 AM, Austin Franklin at [EMAIL PROTECTED] wrote: > > Roy, > >>> >>> I see how size can have a merit (which is a relative ratio), >> and range, as >>> they apply to dynamic range. Size in the fact that the largest >> signal is N >>> times larger than the smallest...and range in that you can say >> "all integer >>> values from 1:1 to N:1". BUT...realize that "all integer >> values from 1:1 to >>> N:1" really denotes a resolution over a particular "range" >> too...that you >>> have N discrete values. >> >> Yes, but I never said "integer". In the real-world i.e. analog, there no >> reason why any real number couldn't be used. What's wrong with going from >> 1:1 to 1.01:1 to 1.02:1 ... > > Because noise is 1, and you can only measure in increments of noise. In a > system that has noise of, say, 1V, you certainly can't measure 1.01V, now > can you? You probably haven't seen the post yet. But, I've actually demonstrated that you can in that post about "noise" and the TIFF file that you can easily print out and measure with your densitometer. > >> Here's why I have a problem with the "concept of resolution": >> >> Let me go through a simple example of a (semi-idealized) scanner. >> >> Here's the basic specs of the scanner: >> Density Range: 0D to 3.6D >> Bit Depth: 12 bits >> Number of levels: 4096 >> >> A couple of simple observations: >> The density range is also 12 photographic stops -- each stop is .3 of >> density so 12*.3 = 3.6 >> You can chop up the density range into 12 one-stop ranges i.e.: >> 0 to .3, .3 to .6, .6 to .9 ... etc to 3.3 to 3.6 >> >> Photographically and human perception wise each of these one-stop >> ranges are equivalent in size. >> >> So now let's chop the density range into the 4096 levels. The >> density range 3.6 divided by 4096 gives a little less than 0.001D >> per level. Approximately, 300 levels for each of the 12 one-stop >> range. Sounds like a great concept of resolution, doesn't it? >> We get a new level every 0.001D change in density -- it sure >> looks like a resolution of 0.001D. > > But that's not how scanners work. They know NOTHING ABOUT density values at > all! They only know photons, and how many photons the CCD sees. They see > relative values output PURELY AS A VOLTAGE (or possibly current), and that > voltage has a range, and has noise. You can only measure as accurately as > noise, and as such, noise defines the resolution of that system. > > I really wish you'd read what I write and not snip out of context. Immediately after the above paragraph I wrote: Fine, but the trouble is: scanners don't work anywhere even remotely close to that scenario. This is what scanners actually output as the levels: The first one-stop range contains 1/2 of all the levels, the next on contain 1/2 of the remaining ones, etc. until the last one. > >> Austin, don't take my word or the web's word for it. Try it yourself. > > Roy, I've designed film scanners, and have been designing digital imaging > systems for over 20 years. I KNOW how they work. You may know scanners inside and out. But with scanners, resolution and levels are all based on QUANTIZATION noise or more accurately QUANTIZATION ERROR. You may pick this quantization based on the real random noise of the system, but all the properties about resolution and number of levels are based on the properties of quantization. The true random noise of the input signal has VERY DIFFERENT properties. Quantization noise is a hard limit on resolution, but RANDOM noise presents no such boundary on resolution. With multiple samples that are averaged you can increase your resolution accuracy. - This is why they have some high end scanners and software that take multiple scan passes. The scanners are designed so that quantization noise is much less than the input signal random noise. With a single pass the random noise is the limiting factor and the bottom couple of bits in the output are just noise -- no information. With multiple passes you average several samples getting a more accurate measurement. You are increasing your resolution beyond the random noise level; when you get down to the quantization level its a hard limit on resolution. That's the best you can do. > > Austin > Roy Roy Harrington [EMAIL PROTECTED] Black & White Photography Gallery http://www.harrington.com Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] Re: dynamic range discussion
At 08:37 PM 9/1/2002 -0700, Bruce wrote: >Please, enough already with the dynamic range argument. I want to learn >about scanners. > >Thanks. >-bruce Bruce, You've made a common mistake. Once upon a time, scanners were the focus of this list. However, it has now become the domain for the all important discussion of DYNAMIC RANGE. The dynamic range storms tend to last for weeks but subside once a dead horse gets beaten to pulp. -JimD Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] FS2710 to ---?
I'm curious if there are list members who made the step to upgrade from the FS2710 and to what. I'm overall quite pleased with the 2710, and feel that I've put in a lot of time learning how to get the most from it. I'm sure others probably experienced the same thing. I'm interested to know what exactly, but empirically, you noticed different after the upgrade. Did anyone go from the 2710 to the 4000? The area I'd most like to see improvement in is shadow noise, but an overall higher resolution sounds attractive, notwithstanding the larger files. I'm curious how much real-world difference this higher res makes, and in what circumstances it's most noticeable. I'd also like batch scanning, but that's a seperate question. Thanks for your time. Ken Durling Visit my new easier-to-browse PhotoSIG portfolio: http://www.photosig.com/viewuser.php?id=203 Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] Re: FS2710 to ---?
I did not, but Roger Smith has. He went to a Minolta Dual Scan II. Rather than try to speak for him, perhaps he will comment if he is around. I can tell you that Roger showed me some comparison scans. The main areas I saw for improvement were: Cleaner shadows with more detail, helped by Vuescan long scan provision. Overall more detail. Increased problems with surface defects and grain. Personally, as an owner of the Minolta Dual II, I would not suggest this upgrade path. Depending upon your budget, you might consider the Canon FS 4000. Another person on this list did buy a FS4000 (Howard). He can also speak for himself. In our correspondence, his complaints were that he was unhappy with the shadow noise, didn't like the Canon software (since updated and somewhat improved), and found the scanner slow. I saw some of his sample scans, and it is a definite move up from the FS2710, and also has an IR cleaning program. Howard ultimately moved to a Polaroid SS4000+, which is a scanner I also have used. To me, the SS4000+ is one of the best compromises, as all scanners are. It is more costly than the FS4000, by a fair amount (at least it was, possibly prices are down). It doesn't have an IR cleaning hardware (has a software process that is good, but not up to what ICE can do, and it is still not ported to Mac) but is also less required due to the diffused lighting. It is also the same basic unit as sold as the Microtek 4000tf. The firewire connection is very fast. For a lower price, and slightly less clean shadows, but otherwise a very good machine, consider the SS4000 (rumors have it limited quantities have become available as used refurbs with full Polaroid warranties and Silverfast 5.5 at a fair price) or if you are not comfortable with Polaroid, consider Microtek's 4000t, which is the same model, which may still be available new in some places. The SCSI II connection is not as fast as the Firewire, but is still no slouch. I have not used Nikon scanners, which I suppose are your only other options as an upgrade. There is the Coolscan IV (LS40) which is 2900 dpi or the LS-4000 which is 4000 dpi. These are the more costly models. They do have IR cleaning, and several other "features", which some people call defects and others call things to be worked around. Primefilm has a new 3600 dpi scanner, and also made the Kodak RF 3600 (also 3600 dpi). Neither seems to have made a major impact in the market, so far. I understand the main complaint with the Kodak was software which has been updated. Art Ken Durling wrote: > I'm curious if there are list members who made the step to upgrade > from the FS2710 and to what. I'm overall quite pleased with the 2710, > and feel that I've put in a lot of time learning how to get the most > from it. I'm sure others probably experienced the same thing. > > I'm interested to know what exactly, but empirically, you noticed > different after the upgrade. Did anyone go from the 2710 to the 4000? > > The area I'd most like to see improvement in is shadow noise, but an > overall higher resolution sounds attractive, notwithstanding the > larger files. I'm curious how much real-world difference this higher > res makes, and in what circumstances it's most noticeable. > > I'd also like batch scanning, but that's a seperate question. > > Thanks for your time. > > > Ken Durling > > Visit my new easier-to-browse PhotoSIG portfolio: > http://www.photosig.com/viewuser.php?id=203 > > > Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] Re: Epson 2200 does it exist?
Though I haven't bought one yet I am planning to. The CompUSA in Monroeville, PA has 4 sitting on the shelf. Howard Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] RE: Dynamic range
> > Roy, > > > > Gee, Austin, here again you snip totally out of context. I DIDN'T > say the following quote. Vincent said it and I explicitly cited > him as the author. > > >> "Dynamic range is the ability to distinguish tonal differences." I thought that this was what YOU were quoting, as it has double quotes around it...not the whole thing. But YOU DID write this: > >> The numbers in the 8-bit file go from 0 to 255, in the 12-bit > file they go > >> from 0 to 4095. These numbers are NOT signal values, in no way is the > >> signal represented by the value 100 twice the size of the signal > >> represented > >> by the value 50. > > > > Well, yes it is. It's a direct reading of voltage from the CCD. It has > > nothing to do with density values, the human eye, logs or > anything. If your > > A/D measure, say, 1V/count...then 100 IS twice as many volts as 50. > > Again, this is the THIRD time I've explicitly stated that the data in > the 8-bit file I'm talking about has been altered by Levels or Curves. > The numbers no longer resemble the output of the A/D of the scanner. But how does that matter? The 8 bit file does NOT NOT NOT have the same dynamic range as the 16 bit file, unless the data in the 16 bit file didn't even have 8 bits worth of dynamic range in the first place. > I really feel like pulling an Austin, here. How about this out of context > snip from the above paragraph: That's not fair, Roy. The ONLY thing that was apparently NOT said by you was the paragraph YOU included but did not quote OR put ">" marks on. The rest WAS yours, right??? How is someone supposed to keep track of what you say and not say, if you don't clearly demarcate it? Austin Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] Re: [filmscanners_Digest] filmscanners Digest for Tue 3 Sep,2002
I have been reading the ongoing discussion regarding dynamic range and it appears to be approaching the discussion about how many angels can sit on the head of a pin. There is a practical side of dynamic range however and that is this, " How much information can I get out of the shadow areas of Velvia film. This is the real world test. When I look at fuji's film databook, it appears that the Dmax of the green sensitive layer is closer to 4.0 than 3.5. So in order to get shadow detail out of this area you need a scanner with dynamic range. I don't really care how closely you divide up the numbers somewhere along the line I need a scanner to get that detail. It seems to me that drum scanners did the job reasonably well using 8 bits per channel. If you have a scan with a lot of noise in the shadows, who cares whether the noise is divided into big chunks (8 bit files) or tiny chunks (16 bit files), it is still noise. My two bits worth Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] Re: FS2710 to ---?
At 2:46 PM -0700 9/2/02, Ken Durling wrote: >I'm curious if there are list members who made the step to upgrade >from the FS2710 and to what. I'm overall quite pleased with the 2710, >and feel that I've put in a lot of time learning how to get the most >from it. I'm sure others probably experienced the same thing. > >I'm interested to know what exactly, but empirically, you noticed >different after the upgrade. Did anyone go from the 2710 to the 4000? > >The area I'd most like to see improvement in is shadow noise, but an >overall higher resolution sounds attractive, notwithstanding the >larger files. I'm curious how much real-world difference this higher >res makes, and in what circumstances it's most noticeable. Hi Ken, I went from the FS2710 to the Minolta Scan Dual II (2820 ppi). On the positive side, the Minolta gave slightly sharper scans with better shadow detail (especially with VueScan). It also has a four-slide holder. On the negative side the Minolta tends to emphasize dirt and scratches, which can be a problem with older slides and negatives. Regards, Roger Smith PS: I agree with Art's comments - I could have written them myself :-) At 3:58 PM -0700 9/2/02, Arthur Entlich wrote: >I did not, but Roger Smith has. He went to a Minolta Dual Scan II. > >Rather than try to speak for him, perhaps he will comment if he is around. > >I can tell you that Roger showed me some comparison scans. The main >areas I saw for improvement were: > >Cleaner shadows with more detail, helped by Vuescan long scan provision. > >Overall more detail. > >Increased problems with surface defects and grain. Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] Re: dynamic range discussion
> If I Knew anything about running a list I'd start a "SCANNERS" list and have two or >three references - one as per Julian , one per Austin and one other. People could >choose who they wanted to believe. If this ongoing crap started up it certainly would >not be posted. Maybe they would then take their bitching somewhere else and then >leave the list for those of us who want to learn and further the discussion about scanning. > From: "JimD" <[EMAIL PROTECTED]> > Date: 2002/09/03 Tue AM 08:18:39 GMT+12:00 > To: [EMAIL PROTECTED] > Subject: [filmscanners] Re: dynamic range discussion > > At 08:37 PM 9/1/2002 -0700, Bruce wrote: > >Please, enough already with the dynamic range argument. I want to learn > >about scanners. > > > >Thanks. > >-bruce > > Bruce, > You've made a common mistake. > > Once upon a time, scanners were the focus of this list. > However, it has now become the domain for the all > important discussion of DYNAMIC RANGE. > The dynamic range storms tend to last for weeks but subside > once a dead horse gets beaten to pulp. > -JimD > > > Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] Re: FS2710 to ---?
At 10:16 PM -0300 9/2/02, Roger Smith wrote: >Hi Ken, > I went from the FS2710 to the Minolta Scan Dual II (2820 >ppi). On the positive side, the Minolta gave slightly sharper scans >with better shadow detail (especially with VueScan). It also has a >four-slide holder. > On the negative side the Minolta tends to emphasize dirt and >scratches, which can be a problem with older slides and negatives. Hi Ken, I forgot to mention I will be away for a couple of weeks, so I won't be able to continue this conversation for a while. I hope you get some additional helpful comments. Regards, Roger Smith Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] RE: dynamic range discussion
The topics of density range and dynamic range are relevant and pertinant to scanners and scanning; unfortunately, the discussion has taken on a life of itsown and ranged away from what is relevant and pertinent to scanning and scanners to what is of interest to engineers and academics. This is has gotten both out of controland repetitive for the most part, although of recent hidden beneath the clutter a few gems of clarity and advancement of the discussion have appreared only to be lost in the chatter that they were a part of. My fear with proposals such as you are suggesting either in jest or in seriousness is that they often define those things of relevance to scanners and scanning as being cookbook "how to" recipes of how to resolve some particular empirical practical problem of a hardware, software, or workflow nature, as being battles over which scanner or software is better or best in response to some subscribers question as to what hardware or software they should buy, and as being superficial discussions of diagnosis of pragmatic related issues such as if it is better to scan positive films or negative films, film or prints, one type of film or paper over another type of film or paper. The result is typically that all technical discussions of more than a superficial nature are abandoned and anything that is not in the form of advice or solutions to "how to" or "which is better" questions gives rise to a chorus of complaining subscribers who only want to talk about what is important to them. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of [EMAIL PROTECTED] Sent: Monday, September 02, 2002 8:39 PM To: [EMAIL PROTECTED] Subject: [filmscanners] Re: dynamic range discussion > If I Knew anything about running a list I'd start a "SCANNERS" list and have two or three references - one as per Julian , one per Austin and one other. People could choose who they wanted to believe. If this ongoing crap started up it certainly would not be posted. Maybe they would then take their bitching somewhere else and then leave the list for those of us who want to learn and further the discussion about scanning. > From: "JimD" <[EMAIL PROTECTED]> > Date: 2002/09/03 Tue AM 08:18:39 GMT+12:00 > To: [EMAIL PROTECTED] > Subject: [filmscanners] Re: dynamic range discussion > > At 08:37 PM 9/1/2002 -0700, Bruce wrote: > >Please, enough already with the dynamic range argument. I want to learn > >about scanners. > > > >Thanks. > >-bruce > > Bruce, > You've made a common mistake. > > Once upon a time, scanners were the focus of this list. > However, it has now become the domain for the all > important discussion of DYNAMIC RANGE. > The dynamic range storms tend to last for weeks but subside > once a dead horse gets beaten to pulp. > -JimD > > > Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] RE: dynamic range discussion
I agree. This _is_ the place to discuss dynamic range with respect to film scanners. I don't think anyone can reasonably complain about it, as long as it's labeled as such in the subject line. It's no harder to hit Delete on something that says Dynamic Range in the subject than it is to hit Delete on something that says Get Your Viagra Now. -- Ciao, Paul D. DeRocco Paulmailto:[EMAIL PROTECTED] > From: Laurie Solomon > > My fear with proposals such as you are suggesting either in jest or in > seriousness is that they often define those things of relevance > to scanners > and scanning as being cookbook "how to" recipes of how to resolve some > particular empirical practical problem of a hardware, software, > or workflow > nature, as being battles over which scanner or software is better > or best in > response to some subscribers question as to what hardware or software they > should buy, and as being superficial discussions of diagnosis of pragmatic > related issues such as if it is better to scan positive films or negative > films, film or prints, one type of film or paper over another type of film > or paper. The result is typically that all technical discussions of more > than a superficial nature are abandoned and anything that is not > in the form > of advice or solutions to "how to" or "which is better" questions > gives rise > to a chorus of complaining subscribers who only want to talk about what is > important to them. Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] RE: dynamic range discussion
This discussion WAS, at one time, about scanning. I have tried to keep it about scanning, as well as have a few others. This "topic" IS directly related to scanning, and is, in my opinion, and important aspect of film, film scanning, digital image manipulation and printing. Unfortunately, for this list, and the other lists that this discussion has been discussed on, the discussion has diverged to many other things, losing sight of film scanning. It's really too bad, because there are some people here who are very qualified to discuss this as it relates to scanners, and there are people here who want to understand it, as it relates to scanners. Austin > > If I Knew anything about running a list I'd start a "SCANNERS" > list and have two or three references - one as per Julian , one > per Austin and one other. People could choose who they wanted to > believe. If this ongoing crap started up it certainly would not > be posted. Maybe they would then take their bitching somewhere > else and then leave the list for those of us who want to learn and > further the discussion about scanning. > > From: "JimD" <[EMAIL PROTECTED]> > > Date: 2002/09/03 Tue AM 08:18:39 GMT+12:00 > > To: [EMAIL PROTECTED] > > Subject: [filmscanners] Re: dynamic range discussion > > > > At 08:37 PM 9/1/2002 -0700, Bruce wrote: > > >Please, enough already with the dynamic range argument. I > want to learn > > >about scanners. > > > > > >Thanks. > > >-bruce > > > > Bruce, > > You've made a common mistake. > > > > Once upon a time, scanners were the focus of this list. > > However, it has now become the domain for the all > > important discussion of DYNAMIC RANGE. > > The dynamic range storms tend to last for weeks but subside > > once a dead horse gets beaten to pulp. > > -JimD Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] RE: [filmscanners_Digest] filmscanners Digest for Tue 3 Sep,2002
Jonathan, > I have been reading the ongoing discussion regarding dynamic range and it > appears to be approaching the discussion about how many angels can sit on > the head of a pin. There is a practical side of dynamic range however and > that is this, " How much information can I get out of the shadow areas of > Velvia film. This is the real world test. When I look at fuji's film > databook, it appears that the Dmax of the green sensitive layer is closer > to 4.0 than 3.5. So in order to get shadow detail out of this area you > need a scanner with dynamic range. That's actually one of the issues...you need a scanner with DENSOTY range, not dynamic rangeyou can capture any density range you want with any dynamic range...they are not the same...but, if you want the DETAIL in the shadow detail, yes, you do need DYNAMIC range. That's one of the points. Dynamic range is about tonal resolution, and not about ability to capture a density range. > I don't really care how closely you > divide up the numbers somewhere along the line I need a scanner > to get that > detail. Exactly, and that is what dynamic range is. Those who equate it with density range are not understanding that they are different, and why...again, one of the big issues, as there are a lot of people who, through misinformation, have been led to believe the two are the same. > It seems to me that drum scanners did the job reasonably well using 8 bits > per channel. What drum scanners scan at 8 bits/channel? Yes, you can get a resultant data output of 8 bits, but the actual scanner scans using much higher bit depth, then applies the setpoints and the tonal curves to the high bit data to give you the 8 bit data file...but the point is, you have to scan using higher bit depth, or you lose the resolution you are "seeking". > If you have a scan with a lot of noise in the shadows, who > cares whether the noise is divided into big chunks (8 bit files) or tiny > chunks (16 bit files), it is still noise. Correct, but 8 bits is insufficient to provide both the density range you want to digitize (because of how scanners are designed) and the dynamic range you need to manipulate the image. Noise is typically much more than 8 bits. Austin Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] Re: dynamic range discussion
Hi Paul- An unfortunate analogy, perhaps. Whereas I "only" get to delete 1 or 2 Viagra ads a day, this list, like others before it, has recently been taken over by an endless stream of going-no-where tit-for-tat back-and-forth, involving only a few list members. As in all of the similar diatribe and counter- diatribe that I have had to delete from other lists, there is little if any attempt by the participants to relate the discussion to relevant questions of scanning. As Laurie pointed out in the paragraph that you omitted to quote. Of course this " _is_ the place to discuss dynamic range with respect to film scanners!" It's the last part of the sentence that has not been addressed, nor do the participants seem to be interested in addressing it. Hence the call for them to take their argument off-list. Bill Morse PhotoProspect Cambridge, MA 02139 on 9/2/02 10:39 PM, Paul D. DeRocco wrote: > I agree. This _is_ the place to discuss dynamic range with respect to film > scanners. I don't think anyone can reasonably complain about it, as long as > it's labeled as such in the subject line. It's no harder to hit Delete on > something that says Dynamic Range in the subject than it is to hit Delete on > something that says Get Your Viagra Now. > > -- > > Ciao, Paul D. DeRocco > Paulmailto:[EMAIL PROTECTED] > Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] RE: Dynamic range -- noise
Roy, > Here's a small example: we have a voltage of 9.37 volts. But then how do you even have a voltage of 9.37V in the first place? How did you measure it at that? > First the quantization situation, we have a digital volt meter that > measures to the nearest volt. The quantization error or noise is > +/- .5 volts. No matter what we do we'll always read 9 volts and be > off by .37 volts. What about the noise in the signal? The noise may bias it up to 10V. > Second we'll try the random noise situation: to be similar to the above > let's say random noise of .5 volts is added to the 9.37 volts. So the > voltage is at least bouncing around from 8.8 to 9.9. How can you have 9.37V with .5V noise? You can't. I think there's some level of basic understanding that's missing here... > So any particular > sample will have a value anywhere in that range. However if you make many > samples and average them the result will converge on 9.37 because > the errors > due to random noise will cancel each other out. Absolutely not. First off, you don't even know that the signal is really 9.37V, because it simply is not, it can't be with a noise of .5V. You can only measure the signal to within +-.5V. Film scanners take a STATIC measurement of the voltage from the CCD, and even if you take more than one measurement, that does not mean you are going to get more precise measurements...you can take a billion measurements, ALL your measurements will be inaccurate to that noise, and "averaging" them does NOT mean you then "average out noise" (I'm not talking about noise that is greater than the noise floor, that's a different issue and getting rid of that noise is a LOT easier, it's characterized). This noise could be caused by some bias, and your "technique" has just failed. If you can't ACCURATELY characterize the noise, you are not going to be able to simply "remove it" by multiple sampling. When scanners do multiple samples, they are removing noise that is way above the noise floor, that is entirely different. > I've been claiming a lot of stuff lately so I'm going to try to back it > up with a real demonstration. Here's a step wedge file that I based on > the 21step wedges that come with Piezography. The top part is the > standard wedge with 21 gray steps from 0% K to 100% K in 5% steps. > The bottom is a duplicate with lots of noise added. You're merely spreading the tones out, so the AVERAGE tone ends up being the same...it's just like using a coarse dither pattern. > The PS command > is Add Noise> 12.5% Gaussian if you want to try it yourself. The > noise is a lot -- magnify to 400% on screen and see it, marquee a > single step and check the histogram. What was 1 grayscale value now > spans more than half the entire grayscale. No matter, as it's the average that matters, and you didn't change the average. I'm not quite clear what this test is supposed to "prove" or show. You KNOW what the source of the noise is, and you KNOW that it's equally dispersed throughout the patch...and this case is completely different than taking voltage measurements, they do not relate. Roy, how do you think dithering works? > Marquee and Histogram 2 > steps and there no obvious steps. However, print the file out on > paper and the step wedge shows through loud and clear. As well it should, I wouldn't expect it not to...given the fact that it's a dither pattern it self, and the average density has not changed... Did you expect it to somehow be different? > Get out the > densitometer and the gray tone measurements of each step match very > well whether you measure the noise-less step or the noisy step. So > the "signal" here is the 5% wedge, the "noise" is large enough to span > many steps in the wedge, but its easy to resolve densities much > closer than the noise level. Nice try, but this is completely irrelevant to measuring voltages. Your noise is completely characterized here, and is evenly dispersed. That is NOT a given with CCD noise, so you can not make the same assumptions. > Download this file, its a TIFF to insure there is no lossy compression. > http://www.harrington.com/21step-noise.tif > > Austin, I hope you are willing to print this out with Piezo and > measure some of the steps. I did, and I don't see anything I wouldn't have expected. I think you think you're showing something that you just aren't showing. Why do you believe the average density on the patches SHOULD be different? Like I said, it's simply like doing a coarse dither pattern. The densitometer has an area it reads, and it averages the area that it reads...and if you add +- so much percent noise over the area, the average is the same. I'm sure it's off by something, but beyond the resolution of my desktop densitometer. I believe you're simply comparing apples and oranges here, and your example, though a nice try, just doesn't model the way film scanners and CCDs and voltages typically work. I know that there ar
[filmscanners] RE: dynamic range discussion
Bill, > An unfortunate analogy, perhaps. Whereas I "only" get to delete 1 or 2 > Viagra ads a day, this list, like others before it, has recently > been taken > over by an endless stream of going-no-where tit-for-tat back-and-forth, > involving only a few list members. As in all of the similar diatribe and > counter- diatribe that I have had to delete from other lists, I agree...and I believe it's actually a lot worse than that. > there is > little if any attempt by the participants to relate the discussion to > relevant questions of scanning. But I strongly disagree with that. I, for one, have ALWAYS tried to keep it about scanners. > Of course this " _is_ the place to discuss dynamic range with respect to > film scanners!" It's the last part of the sentence that has not been > addressed, nor do the participants seem to be interested in addressing it. > > Hence the call for them to take their argument off-list. If someone's comments are NOT directly related to film scanners, then I believe the comment should be off-list, but if it is directly related TO film scanners, then I have no problem with the discussion being on-list. As to why on earth this discussion is even going on and on and on and on and on...it does simply astound me. The topic is simply not that difficult, but for some reason, some others want to make it that way. Unfortunately for me, I seem to be the one that Roy and Julian keep hounding with interminable verbosity. Sigh. I know I am tired of it, and find this really a huge waste of time. Especially given how it simply is not going anywhere, and that I doubt it ever could, given the personalities involved. Austin Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
[filmscanners] RE: dynamic range discussion
Austin, >If someone's comments are NOT directly related to film scanners, then I >believe the comment should be off-list, but if it is directly related TO >film scanners, then I have no problem with the discussion being on-list. But there is the rub. Each and every commentator thinks that his or her comments are directly related to scanners and scanning whether or not anyone else thinks so. Most of the off base remarks are made and sneak in by way of examples, illustrations, analogies, or the like where someone relates a statement concerned with dynamic range as it relates to scanners and scanning to something like audio, film densities, signal to noise rations, electical current and resistance, or music. Next thing you no everyone is off and running in that direction along with all the other directions forgetting all about making any direct explicit statements to the scanner and its operation or to scanning. What is even worse for many of us is that all the electrical engineering formulas and debates over what the proper meaning of the elements in those formulas and the formulas themselves actually are even when there is agreement regarding the expression of the formula is justified by everyone as somehow legitimate since it is concerned with the defenition of the concepts which all agree is a prerequisite of any meaningful discussion of how the concepts relate to scanners and scanning. It seems that everyone has to get in the last word and no one is willing to drop the discussion and ignore the other parties without responding to their latest remarks - be they right or wrong. As I have said to you off list and to others on list, the last round of back and forths has been more productive than earlier ones for me in that some new little gems of insight have arisen from the clutter of the garbage which had not been there before. But I am not sure that enduring protracted repetition of non-productive debate which produced little that was new news was worth it to obtain a few crumbs of insight every now and then. If the topic was of central concern to me, I might be willing to endure riding the wheel in order to get a few bits of wisdom or insight every several turns of the wheel; but I would want to do it in private conversations off list (as I have with you and others) or on a list dedicated to the technical engineering aspects and details pertaining to the topic and its issues and not on a public list where most members could care less about the technical details and who is or is not scientifically correct in their definitions and use of technical concepts. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Austin Franklin Sent: Monday, September 02, 2002 11:59 PM To: [EMAIL PROTECTED] Subject: [filmscanners] RE: dynamic range discussion Bill, > An unfortunate analogy, perhaps. Whereas I "only" get to delete 1 or 2 > Viagra ads a day, this list, like others before it, has recently > been taken > over by an endless stream of going-no-where tit-for-tat back-and-forth, > involving only a few list members. As in all of the similar diatribe and > counter- diatribe that I have had to delete from other lists, I agree...and I believe it's actually a lot worse than that. > there is > little if any attempt by the participants to relate the discussion to > relevant questions of scanning. But I strongly disagree with that. I, for one, have ALWAYS tried to keep it about scanners. > Of course this " _is_ the place to discuss dynamic range with respect to > film scanners!" It's the last part of the sentence that has not been > addressed, nor do the participants seem to be interested in addressing it. > > Hence the call for them to take their argument off-list. If someone's comments are NOT directly related to film scanners, then I believe the comment should be off-list, but if it is directly related TO film scanners, then I have no problem with the discussion being on-list. As to why on earth this discussion is even going on and on and on and on and on...it does simply astound me. The topic is simply not that difficult, but for some reason, some others want to make it that way. Unfortunately for me, I seem to be the one that Roy and Julian keep hounding with interminable verbosity. Sigh. I know I am tired of it, and find this really a huge waste of time. Especially given how it simply is not going anywhere, and that I doubt it ever could, given the personalities involved. Austin Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message
