Re: filmscanners: This Gamma Thing...?
Tom writes ...
Thanks for the explanation. Now I just need to get some kind of idea
of a
good value for gamma. Windows defaults to 2.2. My scanner software
defaults
to 1.4. If I change the scanner software to gamma=2.2 images look
WAY too
bright... Why the difference?
We need to be a bit careful about what your scanner's gamma (1.4)
means. Is it the scanner's "absolute" gamma, or is it a request to
modify the data's gamma by a relative amount ("relative" gamma). It
is difficult to know and answer your question.
My "guess" is it is a relative gamma parameter. It asks you "how
much do you want this scanner's data to be changed", and it is not
asking what your Windows gamma is. That is, if you imply 2.2, then
you imply "2.2 on top of 2.2", which will be way too much. If you
imply 1.0, then you mean don't change a thing, and you simply put your
scanner data in Windows' 2.2 gamma. In between is probably some
optimal value ... it may be 1.4 ... but then your scanner software
probably had no idea (exactly). You need a way to match what you see
on your monitor to what it's supposed to look like ... eg, light table
for your slides, or good proofs for your negatives.
shAf :o)
Re: filmscanners: The K in CMYK
IronWorks writes ... It stands for black. The letter "B" was already taken for something else, I don't recall what, in the printing industry. I won't argue it stands for "black" ... but do not think of it as "the" black. That is, cyan+magenta+yellow should be "black", but in reality it is somewhat muddy. The 'K' is actually a component of the inkset which compensates and make what should be "black" really black. For example, if you check CMYK values for "pure" black ... it might be C=70%, M=70, Y=70, K=90 ... as opposed to 0,0,0,100 shAf :o) | Hello List, | | Just out of old fashioned curiosity: What does the K in CMYK stand for? | | | Tom | |
Re: filmscanners: Kodak RFS
A friend of mine got the Kodak scanner when it first came out. It is a long story but he has had trouble all the way. Finally today, Kodak said he could return it and he is ordering the new Nikon. It sounds like Kodak was not really ready for prime time. Apparently there is a focusing problem when scanning negatives. Because of the curvature of the negative the scans are sharper at the sides then they are in the center. I was aware of this but it wasn't a big concern for me. Anyway they have come up with a firmware upgrade and were looking for beta testers to try it out. I agreed and will let you know of the improvement. (if any) I'm going through post-purchase cognitive dissonance since I just ordered a 3600. Wondering if I should have gotten a Scan Dual II or Canon 2710, and used the saved $600 to buy a new monitor:~( -Berry -- Steve Traudt Synergistic Visions Photography P.O. Box 2585 Grand Junction, CO 81502 Web Site: www.synvis.com *** "Be glad of life because it gives you the chance to love and to work and to play and to look at the stars." -Henry van Dyke
Re: filmscanners: This Gamma Thing...?
My understanding as to a short answer is that essentially the gamma curve is inverse to the curve of the phosphors' luminosity - one is concave, the other convex. I'm really not clear either, though. I've read a lot but it hasn't really hit home. Maris - Original Message - From: "Frank Paris" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Saturday, February 03, 2001 12:42 AM Subject: RE: filmscanners: This Gamma Thing...? | I know you've got a smily face, but he was asking for a technical answer, | and if you think carefully about what each word means in the quoted | definitions, those definitions are very clear. But what he needs is a | complete answer, which I didn't give. Why do we need gamma in the first | place? I've read about it, but off the top of my hat I forget the complete | answer. The whole visual system is nonlinear: the response of the cones in | our eyes to color stimulus, the response of the phosphors to electron | stimulation, the amount of flare off our monitors, etc. I forget all the | factors. But gamma attempts to compensate for all this nonlinearity. | | Frank Paris | [EMAIL PROTECTED] | http://albums.photopoint.com/j/AlbumList?u=62684 | | -Original Message- | From: [EMAIL PROTECTED] | [mailto:[EMAIL PROTECTED]]On Behalf Of Henry Richardson | Sent: Friday, February 02, 2001 8:24 PM | To: [EMAIL PROTECTED] | Subject: RE: filmscanners: This Gamma Thing...? | | | From: "Frank Paris" [EMAIL PROTECTED] | | Here is Giorgianni and Madden's definition from "Digital Color | Management": | "Exponent of a power-law equation relating CRT luminance to | control-signal | voltage". Also, "The slope of the straight-line portion of a CRT | characteristic curve relating log luminance to log voltage." | Anyhow, that's | why if you play with it, it changes the appearances of images on the | screen. | You're basically changing the voltage applied to the phosphors given a | certain digital input value, thus changing the luminance. You're changing | the shape of the curve of RGB value vs. voltage applied. | | I bet that will satisfy his curiosity and teach him not to ask questions. | :-) -- By the way, notice the smiley face -- I'm only joking. | _ | Get your FREE download of MSN Explorer at http://explorer.msn.com | | |
filmscanners: This Gamma thing version 2.0
Hi Gang, No, I will not seize fire. My questions keep popping up and I demand answers!! :-)) Alright. This mysterious gamma controls the way colors are displayed on the monitor through some exponential function of some kind. Fine! Here I am. Spending hours trying to get the gamma just right so that all my pictures will look great on any platform. And then I hit the print button... Then what?? In short: How does the gamma setting affect the output when the image is printed out on paper? Should I have two different files: One with gamma=1 for printing, and one with gamma=2.2 for web publishing? Thanks, Tom
Re: filmscanners: This Gamma Thing...?
In line with shAF's white and black point setting suggestion, there is an excellent site at http://www.aim-dtp.net/aim/index.htm, very professional but understandable and lots of how-to-do-its. There is a monitor calibration section there, and a good walk-through of the white and black point settings at http://www.aim-dtp.net/aim/calibration/blackpoint/crt_brightness_and_contras t.htm Maris - Original Message - From: "shAf" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Saturday, February 03, 2001 12:48 AM Subject: Re: filmscanners: This Gamma Thing...? | Tom writes ... | | ... | It's something with the way monitors show images, but what exactly | is it?? | I notice that my scanner software has a gamma adjustment and playing | with | it I noticed that it changes the way the image appear on the screen. | | More than monitors, most devices have a specific gamma associated | with them ... scanners, printers, digital cameras. | | But what exactly is this mysterious gamma thing? | | Each device has an associated "black" and "white", both of which | are generally similar across all devices (forget for now the color of | white, eg warm vs cold). Between black and white however, is how a | device responds to the data (eg, monitor), or its stimulation by light | (eg, camera+film). This response is generally refered to as the | device's "gamma".
Re: filmscanners: OT: dyesub printers (long)
Arthur Entlich wrote: [stuff about dye sub] There seemed to be stuff on the Epson list that dye sub prints may not last as long as pigment based inkjet prints. Anyone have any ideas on dye sub longevity? Rob
Re: filmscanners: This Gamma Thing...?
Hello all I have been lurking for a while now but be very interested in the technical aspects of scanning. With the help of on of the URLs given I found this article http://www.w3.org/TR/PNG-GammaAppendix.html which is written in a way where even I understand it (which means everyone else will too) Greetings Theo from downunder shAf wrote: Tom writes ... ... It's something with the way monitors show images, but what exactly is it?? I notice that my scanner software has a gamma adjustment and playing with it I noticed that it changes the way the image appear on the screen. More than monitors, most devices have a specific gamma associated with them ... scanners, printers, digital cameras. But what exactly is this mysterious gamma thing? Each device has an associated "black" and "white", both of which are generally similar across all devices (forget for now the color of white, eg warm vs cold). Between black and white however, is how a device responds to the data (eg, monitor), or its stimulation by light (eg, camera+film). This response is generally refered to as the device's "gamma". This type of response is complex, but can be simplified and modeled by a mathematical power function ... the gammas we all refer to as (eg) 1.8, or 2.2, even 1.4 are exponents of this power function called gamma. My scanner software defaults to gamma=1.4. It this an optimal value? If not, what is a better value? It may indeed be your scanner's optimal value ... like I said, each device has its own. However, don't let the math intimidate you. The important parameters to first understand are "black" and "white" ... if everything inbetween looks good, then your gamma is probably ok too. To get it perfect ... further reading: Charles Poynton's color and gamma FAQ: http://www.inforamp.net/~poynton/ If you use Photoshop: "Basic Color Theory for the Desktop" http://www.adobe.com/support/techguides/color/colortheory/main.html nighttime reading: Bruce Fraser's "Real World Photoshop" shAf :o)
Re: filmscanners: real value?
I don't know if it is worldwide, but I believe ALPS has abandoned their dye sub product line, perhaps only supporting it with consumables. They weren't very popular in Canada, and I only saw one dealer who carried them for a short time. The main problems ALPS had were they took too long to get the units out, they were a bit too costly and slow, they couldn't resolve the banding problem with the ribbons, and they didn't or couldn't license out the technology, so companies with more bucks behind them, like HP, Canon, IBM (Lexmark) and Epson were able to create a very strong market following. Finally, inkjet printers have improved their output so much that dye sub has been pretty much been left in the dust, considering other aspects. Dye sub is probably best for self-contained units not requiring a computer, for smaller format prints. The Canon "Home Lab" is an example. Art Gordon Tassi wrote: Ian: I had looked at a some ALPS Electric dye sub printers before getting my Epson. Based on the prices I saw, I would say the 2000 UK Pounds would be at the very top of the line. Their web site ( Search for "ALPS Electric") shows OEM and retail printers.. Their global section shows an office in the U.K. (At Milton Keynes, I believe). The costs shown in the site are the costs to produce a photo, not not the cost of the machine. The cost of a low end printer is the US is about $500. ( I found them at www.alpsusa.com) They do show black and white and color. They seem to print slower than an inkjet. A friend of mine has one and says that the dpi and dimension of the computer output will be the same as the printer output, with the upper limit of the printer's capability being the restriction. Gordon Ian Jackson wrote: Michael, I wonder why there are so few people film scanning then printing with dye sublimation printers? Surely these would fully complement say a 4000 dpi scanner? My only questions are: (1) BW - I see no mention of this is any Dye sub printer literature (2) Where do I find an A3 Dye sub printer under 2000 UK Pounds? Ian - Original Message - From: "Michael Moore" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, February 01, 2001 8:26 PM Subject: Re: filmscanners: real value? Ian, I totally agree. HP has fallen victim to the same short term marketing mentality that infects too many of today's manufacturers and service providers. That said, I do think that their printers at least are much better made than Epson's... What I would really like to see is the old HP mentality applied to their printers, etc., so that we would have truly professional equipment, both in manufacture and design... I will also reply to Art's comment about the price comparison between HP and Epson... wheteher it's the 740, the 870, or the 2000, they all have the print head as part of the printer, so if the darned thing clogs beyond repair, you're scr (my spell-checker just kicked in). As for HP, ain't nobody that I know making third party archival pigment/inks for the darn thing Just give me a Fuji Frontier... Mike Moore Ian Jackson wrote: Michael Moore wrote. Michael, I respect your comment about HP assuming you meant the same oscilloscopes, power supplies etc, that I also used. However HP's Computers, printers, software and service FOR THOSE PRODUCTS, are just not in the same league. Somehow I feel you would not disagree? Ian - Original Message - From: "Arthur Entlich" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Wednesday, January 31, 2001 11:39 PM Subject: Re: filmscanners: real value? Michael Moore wrote: I cut my electronics teeth on HP when I trained as an electronics tech in Th US Navy... Their stuff was always built to last... Last summer I bought an HP 932C... it's built much better than my Epson 740... plus the cartridges come with the nozzles built in so if a print head clogs, you just replace the cartridge... I bought it to replace an Epson that had a clogged print head...(third party inks!)... I thinks it's a load of bull that things can't be made to last... Mike M Didn't the 932C cost a good deal more than the 740 (I'm not on top of the prices on these)? And yes, most anything can be made to last, it costs more RD and usually more in material and manufacturing expense to do so. That's not my point. Making a car last (say a Ford Model T) that can't go above 30 miles an hour, other than as a collectable, doesn't make good sense in a world that demands cars that can go 80 mph for practical considerations. The same is true (and more so) of high tech. If you owned a 10 megabyte harddrive and it was built to last for 50 years, would you still be using it today? Not likely. The darn thing has more value in
Re: filmscanners: Kodak RFS
Steve Traudt wrote: It sounds like Kodak was not really ready for prime time. Now I know they have a spy at Polaroid ;-) Cast your mind back to when the SS4000 first appeared... Art
Re: filmscanners: OT: dyesub printers (long)
Not to be too picky, but I did mention the issues you bring up in your first two comments later on in the posting, when I discuss the ALPS printer. As to point 3, I'm aware how the ALPS printers work. The problem was that the banding was noticeable when light reflected off the image, or if registration of the swipe was off. Some people were able to smooth out these images a bit by using a heat gun on the surface of the image. Most dye sub printers can also use a wax based solid ink (different ribbons or cartridges required). Again, the ALPS showed even more banding texture with these wax based prints. Some people were pleased with the results the ALPS offers, but for any kind of commercial production they were too slow, and prone to problems. They were a "poor man's dye sub", and in that market position they weren't bad. Another company, Fargo (now I believe gone) actually made a fairly inexpensive letter and tabloid dye sub which weren't too bad (at least their later models -- Pictura 310/310e/PrimeraPro). Again, I believe they have gone to bankruptcy heaven. Other companies that either made or branded dye subs includes Kodak, Tally (Spectra*Star DSx), Cal-comp, who also makes/made graphics tablets, QMS (I think now part of Minolta), Tektronix (Phaser II SDX), (now part of Xerox), Shinto Technology, Seiko (the S II and Colorpoint PS) (sidenote: Seiko happens to own another company, or vice versa, called Epson, perhaps you've heard of them...) Art Mike Kersenbrock wrote: Arthur Entlich wrote: you also use a full series of panels. So, place just one dot the size of a period anywhere in the image, and the printer will use up a full set of ink panels to do that. Consumable costs are constant. You do This isn't true of my Alps MD-1300. It would only use a teeny bit of the ribbon when passing over that spot. not want to waste dye sub prints. Unlike an inkjet where you can do small tests, or stop printing early if you see a problem with color balance, etc, no such luck with dye sub. As I mention above, this is true for Alps's dyesub printers, or at least mine. :-) Alps tried to resolve part of this and lower consumable costs by using a series of ribbons rather than panels, but they could never fully resolve the problems with banding caused by the way the inks were laid down on the transfer sheet. Same problem as inkjets that don't print the whole page in one pass of the head. :-) It hasn't been a problem with my machine, but some have reported problems with theirs (at least some models have a home calibration proceedure to "fix" this, don't know if that had been done for those with problems). Mike K.
Re: filmscanners: Kodak RFS
Wow, it's beginning to look Kodak has spies at Polaroid! Dave Hemingway, be warned, Kodak is trying to figure out the concept of customer service... you might finally have some real competition ;-) Art OK Photo wrote: I thought some of you might know that just yesterday I received a call from Kodak asking me if I had any more problems with the scanner other than I already discussed with them. (I've never had a company do that for me before)
Re: filmscanners: The K in CMYK
At 19:06 02-02-01 -0800, you wrote: Hello List, Just out of old fashioned curiosity: What does the K in CMYK stand for? Tom Hi-well would you believe BLACK Check this URL Stuart http://webopedia.internet.com/TERM/C/CMYK.html
Re: filmscanners: x Stuart !! was .. Black Widow or Slidescan Transp'y Adaptor ???
At 18:19 02-02-01 -0600, you wrote: Stuart, Ezio is right. I got one of those little slide adapters with my HP 6300. It's a real joke. I can't believe HP ever made it. I had the same experience as Ezio, except I didn't have to get on my knees and make peanut butter, because I gave up after two or three tries. (Ezio, I guess you have greater perseverance than I do.) Anyway Stuart, if you value your time at all, take the advice you're given and get a real filmscanner. Bob Kehl Hi Bob-I'll send you my address-USD will be fine :-)) I'm not so sure we are comparing like for like here -this Black Widow TA got pretty good reviews here form several sources and its a good price -i think I'll try it anyway and let you know cheers Stuart - Original Message - From: Ezio [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, February 01, 2001 6:35 PM Subject: Re: filmscanners: x Stuart !! was .. Black Widow or Slidescan Transp'y Adaptor ??? Sturat this Black Widow stuff it is exactely the rip-off I had from HP. Then ... if you want to try it ... I can send it to you for free ! It costed to me ... 3 years ago ... 1 month of pure and siny Italian cursing . This is quite enough for me ... I had to get on the knees on some peanuts for 1 week to pay my sins !! .. and to buy a REAL film scanner to be able to scan my slides ... more over ... it is impossible to scan films with this ... the orange casting of the dye is not removable at all . I am not kidding ... when I say I will make you trying ... then eventually either you send it back to me in Italy either you send few bucks to pay it whenever you will decide to keep it . .. Ezio. __ Well it doesn't require power, it has no moving parts and simply sits on top of your scanner its dimensions are H x 100mm, L x 170mm W x 90mm. With a specifiction like this all that's left is for some impressive reviews from magazines and users to let you see what they thought. FilmSCAN 35 produced for Black Widow by SlideScan 'The Results: Quite simply brilliant.' 'All scans I made were superb.' Scanned Image quality 27/30 Ease of use 28/30 Build quality 16/20 Value for money 19/20 'A neat gadget at a fraction of the cost of a dedicated accessory slide scanning adaptor'... its a simple and very neat bit of kit - and very cost effective to boot.' Doug Harman, Deputy Technical Editor, Amateur Photographer Magazine, 29th January 2000. Sincerely. Ezio www.lucenti.com e-photography site - Original Message - From: "Stuart" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, February 01, 2001 1:12 PM Subject: Re: filmscanners: x Stuart !! was .. Black Widow or Slidescan Transp'y Adaptor ??? Hi-here is the url for this device Stuart http://www.blackwidow.co.uk/cgi-bin/bwshop/bw.cgi?ACTION=ENTER+SHOPthispage =frameset.htmORDER_ID=!ORDERID! At 09:22 01-02-01 +0100, you wrote: Stuart, It might be that ''Black Widow'' or ''Slidescan'' adapters are using a different set of tricks to cheat the flat bed scanner and to succeed to scan slides on a flat-bed , but I wasn't able to find any description of this devices on the Web. By the way ... when scanning slides ... this devices are they really letting the scanner to focus on the film surface ? In facts the reflection of the light coming from the lamp is not the only point when scaning slides. To exactely focus the film surface is one of them ... the 1 or 2 mm distance from the glass given by the slide frame is important enough pushing the optical resolution toward the edge. Not to mention all the other factors to be considered. I am firmily convinced that flat-bed scanners cannot succeed in having even a lousy chance to scan slides. Sincerely. Ezio www.lucenti.com e-photography site - Original Message - From: "Stuart" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, February 01, 2001 2:46 AM Subject: Re: filmscanners: x Stuart !! was .. Black Widow or Slidescan Transp'y Adaptor ??? The point u r missing as far as I can see is that the Black Widow and Slidescan slide adaptors are totally different from the transparency hoods you are talking about -these are a prism device that siits on top of a flatbed and is not made by the scanner manfrs like the HP device-test reports from magazines are good stuart At 02:14 01-02-01 +0100, you wrote: Rob is a real gentleman ! The definition he gives about the pure sh@# sold by HP as Slides Adaptor is opening my old wound ! The results are not poor ... simply are not there . After 3 months of absolute pain and real cursing in Italian (the worst possible and the most siny ... don't we have the Pope . ? ) I have given up (it was 3 years ago with a very expensive 6200c ... totally useless ...) and I have bought a Nikon LS-30. Sincerely.
RE: filmscanners: This Gamma Thing...?
Thanks for all the great links that have been posted in association with this thread!
Re: Odp: Future of Photography (was filmscanners: real value?)
In 001901c08bba$9cc7eda0$9513a0d4@a6x4b5, Fotografia - tomasz zakrzewski wrote: 8-10 Megapixels=35mm format. Hmm. 35mm enlarged to 4x6" or 8x10"? Or bigger? No I am talking about the same amount of _detail_ as you would find on a 35mm film frame. Enlarging can't produce detail that is not on the original. Brian Rumary, England http://freespace.virgin.net/brian.rumary/homepage.htm
Re: filmscanners: Vignetting?
In [EMAIL PROTECTED], Stuart wrote: But,of course ,no-one would do so while looking through the viewfinder as this would be extremely detrimental to ones eyesight and if the shutter was released would it not burn the blind ?? I don't think this is true of SLR's, as the image is formed on the ground glass screen and then the eye at the viewfinder looks at that image rather than the sun itself. In a viewfinder camera this might be different, as there is no ground glass screen; you look straight through the viewfinder lens(es). Also the mirror in such a camera covers the shutter blind until the last second, after which the blind moves very fast, I doubt if it would be focused on the blind of film for long enough to have any effect. Brian Rumary, England http://freespace.virgin.net/brian.rumary/homepage.htm
Re: filmscanners: Kodak RFS
Do you know if he firmware upgrade allows the autofocus to operate when negatives are scanned, as opposed to the usual operation where only slides are autofocused and negs are fixed focus? There was little information presented to me other than that Kodak would be in touch with me in the next couple of days to fill in the details of what this beta testing is all about. The RFS allows auto and manual focus for slides at the present. I do not know what direction they will take to improve focusing on negatives. I'm going through post-purchase cognitive dissonance since I just ordered a 3600. Wondering if I should have gotten a Scan Dual II or Canon 2710, and used the saved $600 to buy a new monitor:~( Kodak is quite good about their return policy. Give it a try first and see what you think. Paul http://okphoto.webjump.com P:250-498-2800 F:250-498-6876
RE: filmscanners: The K in CMYK
This is why K is called "process black". It is the black that is used in the printing industry's "process" of color printing. Frank Paris [EMAIL PROTECTED] http://albums.photopoint.com/j/AlbumList?u=62684 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of shAf Sent: Friday, February 02, 2001 11:19 PM To: [EMAIL PROTECTED] Subject: Re: filmscanners: The K in CMYK IronWorks writes ... It stands for black. The letter "B" was already taken for something else, I don't recall what, in the printing industry. I won't argue it stands for "black" ... but do not think of it as "the" black. That is, cyan+magenta+yellow should be "black", but in reality it is somewhat muddy. The 'K' is actually a component of the inkset which compensates and make what should be "black" really black. For example, if you check CMYK values for "pure" black ... it might be C=70%, M=70, Y=70, K=90 ... as opposed to 0,0,0,100 shAf :o) | Hello List, | | Just out of old fashioned curiosity: What does the K in CMYK stand for? | | | Tom | |
Re: filmscanners: This Gamma thing version 2.0
Tom writes ...
Here I am. Spending hours trying to get the gamma just right so that
all my
pictures will look great on any platform. And then I hit the print
button... Then what??
In short: How does the gamma setting affect the output when the
image is
printed out on paper? Should I have two different files: One with
gamma=1
for printing, and one with gamma=2.2 for web publishing?
Possibly (... I know, not much of an answer ...). Understand this
is a bit dependent on your printer manufacturer. Did they write the
driver software for your printer which anticipated a specific gamma.
A consumer type printer like a HP 895 will assume a color space
similar to sRGB (gamma=2.2) is what needs to be printed. However, if
you prefer to use a 3rd party postscript driver for the same printer,
you may indeed have to fine tune a gamma variable.
Usually, you will always be in the ball park with a gamma ~2 ...
as if luminous response for all devices is a function of "area" (an
exponent of '2') ... even our eyes' perception has a similar gamma.
Yet, '2' is never exact, and there is definitely a difference between
1.8 and 2.2.
If you are really curious about all this (... and more ...), then
you'll want to explore color spaces and device profiles, why many of
feel they are necessary, why they are sometimes a headache, how they
are supposed to work together ... scanner=photoshop(and
monitor)=printer. Bruce Fraser is almost everyone's guru on color
("Real World Photoshop" "Real World Scanning Halftones"). He has
some online articles here, but his book is most enlightening.
http://www.creativepro.com/author/home/0,1819,40,00.html
shAf :o)
RE: filmscanners: real value?
Actually, I like the fact that inkjets are somewhat worse and better than inkjets but not that inkjets might be equal to inkjets. Some inkjets are more equal than others. Apologies to Orwell and the list.
RE: Future of Photography (was RE: filmscanners: real value?)
"At the extremely high end, the KAF-16801CE CCD features 16.6 million pixels in a 40804080-pixel array. By using relatively large, 99-m pixels, the device delivers greater light-capturing ability, dynamic range, and SNR than possible with the commonly used smaller pixels. As a result of the pixel size, the dual inline package, which has just 34 pins, measures about 38 mm2 -an eye-catching piece of silicon! The array also includes proprietary on-chip RGB-color filtering to improve color-space performance and sensitivity. The KAF-16801 sells for $3000 to $4000 (1000)." Thus, we are getting there and sooner than I dared hope! Now, when it gets to be affordable, I'll buy one! Custom made CCDs for astronomy have gone as high as 10,000 by 10,000 with the diameter of the sensor being just slightly smaller than the 5 inch blank it was fabricated on. Cost was less than $1,00,000 USD. BW only. Takes a few minutes to read the sensor after a multi-hour exposure. Noise level of around 1 photon per pixel. True 16 bits per pixel (16 stops) range.
Re: filmscanners: This Gamma thing version 2.0
Thank you shAf!
I especially appreciate his articles A Profiling Primer at
http://www.creativepro.com/story/news/0,1819,5710,00.html and Color-Accurate
Inkjets Made EZ (review of 3 profiling software programs) at
http://www.creativepro.com/story/feature/5708.html
Maris
- Original Message -
From: "shAf" [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Saturday, February 03, 2001 11:56 AM
Subject: Re: filmscanners: This Gamma thing version 2.0
| Tom writes ...
|
| Here I am. Spending hours trying to get the gamma just right so that
| all my
| pictures will look great on any platform. And then I hit the print
| button... Then what??
|
|
| In short: How does the gamma setting affect the output when the
| image is
| printed out on paper? Should I have two different files: One with
| gamma=1
| for printing, and one with gamma=2.2 for web publishing?
|
| Possibly (... I know, not much of an answer ...). Understand this
| is a bit dependent on your printer manufacturer. Did they write the
| driver software for your printer which anticipated a specific gamma.
| A consumer type printer like a HP 895 will assume a color space
| similar to sRGB (gamma=2.2) is what needs to be printed. However, if
| you prefer to use a 3rd party postscript driver for the same printer,
| you may indeed have to fine tune a gamma variable.
| Usually, you will always be in the ball park with a gamma ~2 ...
| as if luminous response for all devices is a function of "area" (an
| exponent of '2') ... even our eyes' perception has a similar gamma.
| Yet, '2' is never exact, and there is definitely a difference between
| 1.8 and 2.2.
|
| If you are really curious about all this (... and more ...), then
| you'll want to explore color spaces and device profiles, why many of
| feel they are necessary, why they are sometimes a headache, how they
| are supposed to work together ... scanner=photoshop(and
| monitor)=printer. Bruce Fraser is almost everyone's guru on color
| ("Real World Photoshop" "Real World Scanning Halftones"). He has
| some online articles here, but his book is most enlightening.
|
| http://www.creativepro.com/author/home/0,1819,40,00.html
|
| shAf :o)
|
filmscanners: Vuescan has too much saturation
Ed's really come a long ways with the last few versions of VueScan. Using 6.6.1 I was finally able to make a scan of one of the slides from the groupscan (the infamous bug hunter hat) that had realistic grass, full detail in the hat, and good contrast. I found settings gamma to 2.2 and brightness to 1.5 worked quite well, along with a White Point of .0001 and a black point of 1%. Now I did get WAY too much saturation and did have to back off the red a bit in PS. How would one control saturation in VueScan? The preview and Scan windows did not match the PS image, as they showed a bit of a color cast and no saturation issues. alan
RE: filmscanners: This Gamma Thing...?
On Fri, 02 Feb 2001 22:16:33 -0800 Tom Christiansen ([EMAIL PROTECTED]) wrote: Thanks for the explanation. Now I just need to get some kind of idea of a good value for gamma. Windows defaults to 2.2. My scanner software defaults to 1.4. If I change the scanner software to gamma=2.2 images look WAY too bright... Why the difference? Probably your monitor adjustment and calibration. A 'good value' is a difficult question which has occupied vast amounts of argument. Unity gives equal precision to all values, which might seem a good idea from the data's POV (and Timo Autiokari's) but our perceptual needs are more idiosyncratic - we are very sensitive to brightness variations in the midtones and shadows, less so to highlight differences so precision in the former is usually more important. The optimum value of gamma tends to vary depending on the type of image and what is important to the photographer. Any value is a trade-off. To be more practical, Macs use a system gamma of 1.8 and are historically the de facto standard in imaging. Therefore 1.8 is a 'good value' if you are working with designers who will be using Macs. However Windows machines are much more numerous. If you are aiming at cross-platform medium such as the WWW, 2.2 is probably a safer assumption. There's some stuff on my site about all this, and it's well worth reading Prof Charles Poynton's FAQ about Gamma (link at my site). But don't be too taken in by it - he is talking only about video systems and optimal presentation. We tend to have to worry about data precision as well, through iterations of editing operations. Regards Tony Sleep http://www.halftone.co.uk - Online portfolio exhibit; + film scanner info comparisons
Re: filmscanners: Vuescan has too much saturation
"Alan Womack" [EMAIL PROTECTED] wrote: Now I did get WAY too much saturation and did have to back off the red a bit in PS. I don't think I've ever scanned anything in Vuescan which had too much saturation! (but maybe I like oversaturated images ;) Rob
Re: filmscanners: OT: dyesub printers (long)
"John C. Jernigan" [EMAIL PROTECTED] wrote: Art, Rob, et al, Have you, or any others, any experience with the Olympus P-400 dye sub? The samples I've seen are superb and can print (almost ) 8x10. Not I, but then the reason I just bought an 1160 was to get to A3. :) Rob
filmscanners: Re: looking at the Sun
I'm sure others will chime in on this one, but I can't let that advice go unanswered. Just because the image in an SLR viewfinder is replected up through a pentaprism and a ground glass screen is no reason for complaisance about looking at the sun with such a camera. The efforts to make the screen view as bright as possible makes the light level in the eyepiece just about as dangerous as looking at the sun directly. True, there is some reduction, but in many cases, if not most, it is still bright enough to blind in a short time. Don't do it! Of course, a sunset may have the light attenuated enough by the atmosphere to make it safe. But, if it is uncomfortable to look with the unaided eye, don't gamble on looking through the viewfinder of an SLR. At 01:32 PM 02/03/2001 +, you wrote: In [EMAIL PROTECTED], Stuart wrote: But,of course ,no-one would do so while looking through the viewfinder as this would be extremely detrimental to ones eyesight and if the shutter was released would it not burn the blind ?? I don't think this is true of SLR's, as the image is formed on the ground glass screen and then the eye at the viewfinder looks at that image rather than the sun itself. In a viewfinder camera this might be different, as there is no ground glass screen; you look straight through the viewfinder lens(es). Also the mirror in such a camera covers the shutter blind until the last second, after which the blind moves very fast, I doubt if it would be focused on the blind of film for long enough to have any effect. Brian Rumary, England http://freespace.virgin.net/brian.rumary/homepage.htm
Re: filmscanners: Eagle Creek on Velvia, scanned with VueScan 6.6 on an SS4000
Thanks, Frank. You did a good day's work there. I did especially like your favorite EC 175. Very nice image. Hersch At 08:45 PM 02/03/2001 -0800, you wrote: Here are 54 scans of Velvia at 1280X1024 so you can see some detail. Subject matter: world famous Eagle Creek Trail in the Columbia Gorge on the Oregon side, taken 1/27/2001 on a sunny day. Total length of hike: 10 miles, 5 in and 5 out. http://albums.photopoint.com/j/AlbumIndex?u=62684a=11304982 These photos illustrate what I have been able to accomplish so far with my SS4000 under VueScan and Photoshop, and they have benefited from much information I have gleaned from this list. When you click on a thumbnail, you will only see a 640X480 image. To see the full resolution 1280X1024, you have to click on the 640X480 image. These were compressed by Photoshop using maximum image quality (10), so as JPG's go, they aren't going to get any better. The files average a megabyte each, so may the gods give you patience if you have a slow internet connection and you want to see the full-size images. This is my first usage of Velvia. It is stunning, but it often produces problems for scanning, as I document in my notes on the various images. A couple of times, I couldn't get satisfactory results from VueScan and had to resort to Polacolor Insight. The slides of the canyon in deep shadows required substantial removal of blue cast with Photoshop curves, as I mention in my notes. Often they also required adding some red. I never had to touch green. Not surprisingly, my best results were on images that were either fully illuminated by sunlight, or submerged completely in deep shadows. I could not get good scans from these Velvia slides with mixed sunlight and shadows, even though they looked great on the light table, better than any other slide film I've used with mixed sunlight and shadows, a lighting situation I generally try to avoid, even with negative film. In a few cases, I have shown two different scans of the same slide, one with VueScan and one with Polacolor Insight. In other cases, I show the same scene shot around noon and then three hours later. In every case, the images shot later in the day scanned much better, not to say that the original slides were any better. The heavy blue casts of the VueScan images were not a problem in Photoshop and removing them did not degrade the final image in any way. I always scanned 48 bit TIFF files and operated on them in that mode in Photoshop, then when I was satisfied converted the full-res (4000 dpi) image to 24 bits before saving. No sharpening was performed until after decimating to 1280X1024. In most cases, the sharpening was relatively benign: 75 strength, .75 radius, threshhold 3. I keep all 4000 dpi scans in the original, unsharpened state so that I can fool with them later if I am so inclined. All of these pictures were taken on a tripod. Exposures varied from about 1/30 of a second to about 15 seconds. I took and used the following lenses on this hike: 17mm f2.8, 20mm f2.8, 28mm-70mm f2.8, 135mm f2, 180mm f2.8, and 300mm f4. All are autofocus Nikon lenses in current production except the 17mm, which is a Tokina, also in current production. I shot with a Nikon F100. I don't mind anyone making 3X5 prints from these scans for personal use, or using them as your monitor wallpaper. Frank Paris [EMAIL PROTECTED] http://albums.photopoint.com/j/AlbumList?u=62684
RE: filmscanners: Eagle Creek on Velvia, scanned with VueScan 6.6 on an SS4000
A glorious shot, if I don't say so myself :) In fact, my jaws dropped when I saw it. I've been photographing that bluff for 24 years, and this is the best it's ever looked, thanks to Velvia, the SS4000, and VueScan. Probably my favorite of the series also. Frank Paris [EMAIL PROTECTED] http://albums.photopoint.com/j/AlbumList?u=62684 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Hersch Nitikman Sent: Saturday, February 03, 2001 9:58 PM To: [EMAIL PROTECTED] Subject: Re: filmscanners: Eagle Creek on Velvia, scanned with VueScan 6.6 on an SS4000 Thanks, Frank. You did a good day's work there. I did especially like your favorite EC 175. Very nice image. Hersch
RE: filmscanners: Re: looking at the Sun
The shots I mentioned where I do do this are always extreme wide angle which is no worse than looking up in the sky with the sun at the extreme periphery of our vision. Still, extreme care should be exercised, as you say. Usually what I do is compose with the sun just out of reach then shift slightly without looking in and hope for the best. Frank Paris [EMAIL PROTECTED] http://albums.photopoint.com/j/AlbumList?u=62684 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Hersch Nitikman Sent: Saturday, February 03, 2001 9:17 PM To: [EMAIL PROTECTED] Subject: filmscanners: Re: looking at the Sun I'm sure others will chime in on this one, but I can't let that advice go unanswered. Just because the image in an SLR viewfinder is replected up through a pentaprism and a ground glass screen is no reason for complaisance about looking at the sun with such a camera. The efforts to make the screen view as bright as possible makes the light level in the eyepiece just about as dangerous as looking at the sun directly. True, there is some reduction, but in many cases, if not most, it is still bright enough to blind in a short time. Don't do it! Of course, a sunset may have the light attenuated enough by the atmosphere to make it safe. But, if it is uncomfortable to look with the unaided eye, don't gamble on looking through the viewfinder of an SLR. At 01:32 PM 02/03/2001 +, you wrote: In [EMAIL PROTECTED], Stuart wrote: But,of course ,no-one would do so while looking through the viewfinder as this would be extremely detrimental to ones eyesight and if the shutter was released would it not burn the blind ?? I don't think this is true of SLR's, as the image is formed on the ground glass screen and then the eye at the viewfinder looks at that image rather than the sun itself. In a viewfinder camera this might be different, as there is no ground glass screen; you look straight through the viewfinder lens(es). Also the mirror in such a camera covers the shutter blind until the last second, after which the blind moves very fast, I doubt if it would be focused on the blind of film for long enough to have any effect. Brian Rumary, England http://freespace.virgin.net/brian.rumary/homepage.htm
