Luminous Landscape Forum
Raw & Post Processing, Printing => Colour Management => Topic started by: guyburns on January 17, 2011, 08:02:37 am
-
I'd like to make sure I have a reasonable understanding of what I have learnt from responses to my previous post (http://www.luminous-landscape.com/forum/index.php?topic=50262), by condensing into a few statements all the information from respondents. Correct me if I'm wrong:
1. The best single reference for understanding colour is Hunt's Reproduction of Color, 6th Edition. I hope it's the best, because I've just ordered a copy.
2. Kodachrome has an inherent blue shift caused by the red-sensing layer (and to a lesser extent, the green-sensing layer) having higher densities at any exposure than the blue-sensing layer (p3, http://www.kodak.com/global/en/professional/support/techPubs/e55/e55.pdf).
3. To ensure neutrals remain neutral when projected, Kodachrome was purposely designed to have a blue shift so as to counteract the yellowish light of projection lamps (Hunt: 44, 229-30).
4. For reasons not definitely known, most other slide films do not have a built-in blue shift.
5. A slide scanner can be calibrated with an IT8 target (to counter any scanning inaccuracies) using software such as VueScan or SilverKeeper which generate a colour profile that can be applied to a raw scan to correct for inaccuracies in the scanner. Free software to do the same thing include Scarce (http://www.scarse.org/), Argyll CMS (http://www.argyllcms.com/), and Lprof (http://lprof.sourceforge.net/help/lprof-help.html).
6. Each IT8 target also needs a IT8/CGATS file that contains the colormetric measurements for that target. This text file is required as part of the calibration process. The CGATS file for Kodachrome can be downloaded from FTP.Kodak.com/GASTDS/Q60DATA and is contained in a folder called K3-Data. Info about the colour coding of the IT8 targets is in the document TECHINFO.pdf.
7. Calibrating a scanner using an IT8 target cannot remove the inherent blue cast in Kodachrome slides, it can only remove inaccuracies in the scanning process.
8. The blue cast can be reduced by applying Levels correction in Photoshop using the gamma adjustment (middle slider). Approximate settings are Red 1.19 and Green 1.04 (see reply 21, http://www.luminous-landscape.com/forum/index.php?topic=50262.msg415697#msg415697)
9. Not only Kodachrome, but all slides intended for projection in a darkened room are designed to have contrast substantially higher than that necessary for optimum reproduction as prints. When slides are projected in darkness, the image appears lighter, and this effect is stronger for darker areas of the image. The result is a loss in perceived contrast, which can be counteracted if the contrast of the slide in increased. To quote from Fairchild (p 10, http://www.cis.rit.edu/fairchild/PDFs/PAP02.pdf):
… when scenes are reproduced on transparency film, to be projected in a darkened room, the physically-measured contrast, expressed in logarithmic coordinates, must be about 1.5 times higher than the original scene in order to create an optimum reproduction. However, printed images viewed in illuminated surroundings are optimal when their physically-measured contrast is equal to that in the original scene. This result is described in detail by Hunt.
10. The increased contrast of a slide (as compared to a print) can be counteracted by the appropriate selection of gamma in Photoshop Levels.
11. CIECAM02 (the most recent CIE colour-appearance model) attempts to simulate the appearance of an image in a different environment (such as a darkened room) by including (among other parameters) luminance information about the background. For example, a scanned slide can be given a similar appearance on screen as it would when being projected in a darkened room. A Photoshop plugin, and sample images, can be downloaded from http://sites.google.com/site/clifframes/ciecam02plugin.
I can find no reason among the replies to my original post why Kodachrome should be more difficult to scan than other films, given a good-quality dedicated slide scanner such as a Coolscan 5000. I would have thought the alleged difficulties could be overcome by ensuring that:
• The scanner is calibrated using an IT8 target and the resulting profile applied to the scanned image. This should remove any colour inaccuracies;
• The inherent blue-cast is reduced in Photoshop Levels by a suitable input of gamma to the red and green channels; and
• the high contrast is corrected by altering the overall gamma, again using Levels.
Kodachrome may indeed be more difficult to scan, but why?
Additional Comments Based on Replies
23 Jan 2011
12. The gamma adjustments mentioned in point 8 will vary depending on the color space of the image. The stated numbers (red 1.19 and green 1.04) should work while the scan in still in a linear scanner profile space. If the scan is in another space, such as sRGB, most likely the gamma adjustments will be different.
See http://www.luminous-landscape.com/forum/index.php?topic=50387.msg416119#msg416119
13. When using scanning software provided by the manufacturer of the scanner (e.g. NikonScan for Coolscan devices), and the scanner has not be calibrated with an IT8 target, selecting the Kodachrome setting will likely give better results than a Kodachrome setting in third-party software. This is because the manufacturer of the scanner has probably made an effort to include the RGB sensor characteristics in the Kodachrome setting, whereas third-party software is unlikely to have access to these characteristics, and will assume a generic characteristic.
See http://www.luminous-landscape.com/forum/index.php?topic=50387.msg416244#msg416244: If Silverfast provided Kodachrome LUTs in its software to substitute a Kodachrome target profile then I hope it is adapted per individual scanner model (lamp spectrum, sensor RGB dyes). If Hamrick had to do the same for Vuescan it must have been a hell of a job for him.
See http://www.luminous-landscape.com/forum/index.php?topic=50387.msg416441#msg416441: … here is what Silverfast says on their own web site about their Kodachrome profiles: “… we have implemented generic Kodachrome ICC-profiles for many supported film scanners …”. (emphasis added)
-
I think it's an excellent summary.;D
Regarding item #8, the gamma adjustments required will vary depending on the color space the image is in. The numbers red 1.19 and green 1.04 should work while the scan in still in a linear scanner profile space. If the scan is in another space, such as sRGB, most likely the gamma adjustments will be different. It is easy to do by eye. If the red, green and blue gammas are adjusted so that a neutral mid-tone has equal RGB numbers, that should provide a good starting point. One can also change (reduce) the blue gamma instead of the green.
In answer to your final question, "Kodachrome may indeed be more difficult to scan, but why?", I think the reasons are 1. the high dye density can exceed the dmax of most scanners, and 2. not all scanner software has a magic Kodachrome setting which automatically takes care of items #8 and #9. It's not obvious that the manual adjustments to use are gamma adjustments (which effectively tilt the characteristic curves). Trying to eliminate the blue cast using scanner exposure settings (shifting the curves up or down without tilting) or with white-point/black-point adjustments, just doesn't work very well.
-
The Kodachrome problem and a solution for it are well-explained here: http://www.silverfast.com/highlights/kodachrome/en.html. In a nutshell, the most efficient approach is to profile the scanner for Kodachrome using a Kodachrome target and associated reference file. If you intend to go this route, don't wait years - Kodachrome targets will become scarce because the film and its processing laboratories are all off the market - gone. Once the various providers' current inventories of Kodachrome targets are sold, game over for that approach unless you can borrow or buy existing ones from their owners.
-
Yes, buy a Kodachrome target before it's too late.
But Mark, where is there a good explanation of the Kodachrome problem at the link you provided?
Profiling the scanner with a Kodachrome target alone is not enough. Even with a Kodachrome profile, you still have to activate the special Kodachrome mode in Silverfast or other scanning software. If the scanning software doesn't have a Kodachrome setting, or you want to try doing it better yourself, you have to make manual corrections.
-
Yes, buy a Kodachrome target before it's too late.
But Mark, where is there a good explanation of the Kodachrome problem at the link you provided?
Profiling the scanner with a Kodachrome target alone is not enough. Even with a Kodachrome profile, you still have to activate the special Kodachrome mode in Silverfast or other scanning software. If the scanning software doesn't have a Kodachrome setting, or you want to try doing it better yourself, you have to make manual corrections.
It's not explained in gory technical detail there, but they do say in a nutshell what the basic problem is. And yes, scanning software should have a Kodachrome setting, which most versions of SilverFast and Vuescan both provide. Using that setting with a scanner profile made from a Kodachrome target should provide very decent colour reproduction. Of course the whole idea of an efficient workflow is to minimize the amount of manual intervention needed.
-
It is certainly worth a try to profile your scanner for Kodachrome. If you don’t have profiling software, you may want to download one or more of the free profiling software packages available via the internet. I don’t have the links handy, but should be easy to find with a search.
I’ve used it to profile my scanner for Fuji Velvia and Provia. The profiles produced a very slightly different look than the generic profile I was using and other film specific profiles made for my scanner model. They all produced very similar looks, however, and I can’t say which the best was. I’ve read that my experience is not unusual. Profiling may help some, but it may not provide as big a benefit as you might hope.
Maybe you’ve already tried using the white balance tool in Camera Raw or Lightroom. If not, you may want to give it a try. I’ve found that tool to be the most effective and easiest tool to use tool to remove color casts. In some cases white balance can’t fully remove a color cast, so after using white balance you may also need to use the split toning tool or some other method in Camera Raw, Lightroom or PS. I’ve had the most success with such methods. YMMV
If you haven’t already done so, you may want to check out the “Kodachrome Profiles” article and the “Scanning Guide” available here: http://www.hutchcolor.com/CMS_notes.html
EDIT: Sorry, I just noticed that you are already familiar with the free profiling software.
Profiling the scanner with a Kodachrome target alone is not enough. Even with a Kodachrome profile, you still have to activate the special Kodachrome mode in Silverfast or other scanning software. If the scanning software doesn't have a Kodachrome setting, or you want to try doing it better yourself, you have to make manual corrections.
For a different perspective, you may want to note this quote from the scanning guide: “All traditional scanner adjustments such as highlight and shadow, cast removal, color correction, sharpening, etc. should be done in Photoshop 7 or later.” Of course, you’ll have to decide whether this advice from Don Hutcheson is best for your situation.
-
Yes, Don's stuff is well-researched and great, but get ready to roll-up your sleeves - only a 32 step process to make a good Kodachrome profile without Kodachrome, and best to have a high-end display and a light box along for the ride. Two of the things SilverFast users appreciate are the IT8 profiling process and the grey balance tool (they call it a "pipette" - OK). I've done and published a fair bit of experimentation with their IT8 process, and on the whole I think it's pretty good. They've also had it independently tested by a lab in Germany. It couldn't be easier to profile a scanner - basically a one button-push operation once you have their target. One can always not bother to profile the scanner, but it does save a lot of work especially with Kodachrome, to use a good profile.
If you still need it, the grey pipette, although not the most user-friendly little gizmo to isolate on their GUI - once you get used to that - produces very good colour balance with just about a click or two. The key to success with the pipette is to isolate a few pixels which really should be GRAY. The tool gives you an iterative process of up to four samples. I've found it very effective. This isn't to open a new debate about whether to adjust images pre or post-scanning, but just to mention that these capabilities are there in various versions of the scanning application and they can do a pretty good job, saving work later on.
-
Some extra comments on Kodachrome scanning: Kodachrome target versions, Kodachrome versions.
http://members.klosterneuburg.net/handerle/kodachrome.html
If Silverfast provided Kodachrome LUTs in its software to substitute a Kodachrome target profile then I hope it is adapted per individual scanner model (lamp spectrum, sensor RGB dyes). If Hamrick had to do the same for Vuescan it must have been a hell of a job for him.
Remove line 3 and 4 in the summary I suggest, it confuses. Or just mention a blue cast in scanning before white/grey/black is fixed. Any slide film CMY dye set has to be carefully selected to get an acceptable color in projection light. Two daylight slide films should deliver a similar/acceptable image in projection light, that is the goal. The differences can be more saturated etc to please the crowd that buys the film but in the end your greys should be neutral in projection light, the colors represent the scene more or less and the gamut a bit balanced. I have not seen Hunt's comments how Ektachrome dyes were selected, layers tweaked to get there but similar obstacles must have been along his path then.
The moment you change projection light, change the projection screen, let the cat watch the images ...... colors (typical Ektachrome, Fujichrome, Ektachrome) are no longer similar/matching/acceptable. Observer is changed, illumination is changed. If that delivers a significant blue or red or green cast in one of them to the observer then his conclusion should be color inconstancy due to illumination and observer and not describe it as typical xxxx color. The film was created to be exposed in daylight at the right speed, exposure time, normally developed and projected with the standard projector lamp, heat shield, optics, projection screen, average human eye.
With 90% of color scanning dealing with dyes related to Ektachrome films you can expect that the hardware-software is more directed to that task.
met vriendelijke groeten, Ernst Dinkla
Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/
-
Some extra comments on Kodachrome scanning: Kodachrome target versions, Kodachrome versions.
http://members.klosterneuburg.net/handerle/kodachrome.html
If Silverfast provided Kodachrome LUTs in its software to substitute a Kodachrome target profile then I hope it is adapted per individual scanner model (lamp spectrum, sensor RGB dyes).
met vriendelijke groeten, Ernst Dinkla
Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/
The way it works in SilverFast is that you select the media in the General Tab. If you select Kodachrome, the program defaults to the canned profile LSI provides for Kodachrome AND THAT SCANNER. LSI's canned profiles are made PER SCANNER MODEL. How well their canned profiles perform in your scanner depends on how closely your scanner's behaviour replicates the one they used for generating the profile, so the better behaved the scanner (in terms of performance consistency from one unit to the next) the more satisfactory the canned profile and the less the need for a custom profile. (If you've made a good custom profile, best to use it.)
Of course one other hooker in all of this which seldom gets discussed, but is perhaps the stickiest wicket, is the fact that over many years these transparencies experience colour shifts. The character and extent of it varies depending on a number of storage factors. I've scanned some of my Kodachromes now more than 50 years old - some required a fair bit of "restoration and rebalancing", others much less. No profile can deal with that issue. There are software fixes for this phenomenon but I've generally found manual correction more satisfactory in these cases. Often finding a good black point and a good gray point is all that's required, perhaps aided with a bit of a saturation and contrast boost.
-
Re Crames' comment:
Profiling the scanner with a Kodachrome target alone is not enough. Even with a Kodachrome profile, you still have to activate the special Kodachrome mode in Silverfast or other scanning software. If the scanning software doesn't have a Kodachrome setting, or you want to try doing it better yourself, you have to make manual corrections.
I didn't mention the Kodachrome setting in my summary because I wasn't sure if my understanding was correct. So I have another question based on the two settings available in NikonScan (POS or Kodachrome). Does it matter which slide setting you use, as long as you use the same setting when scanning as you did when calibrating? i.e you can scan Kodachrome under a POS setting as long as you calibrated the Kodachrome target using the POS setting. For the case of this hypothetical, assume that ICE is not used – scanning Kodachrome with ICE under a POS setting causes problems.
-
The way it works in SilverFast is that you select the media in the General Tab. If you select Kodachrome, the program defaults to the canned profile LSI provides for Kodachrome AND THAT SCANNER. LSI's canned profiles are made PER SCANNER MODEL. How well their canned profiles perform in your scanner depends on how closely your scanner's behaviour replicates the one they used for generating the profile, so the better behaved the scanner (in terms of performance consistency from one unit to the next) the more satisfactory the canned profile and the less the need for a custom profile. (If you've made a good custom profile, best to use it.)
Of course one other hooker in all of this which seldom gets discussed, but is perhaps the stickiest wicket, is the fact that over many years these transparencies experience colour shifts. The character and extent of it varies depending on a number of storage factors. I've scanned some of my Kodachromes now more than 50 years old - some required a fair bit of "restoration and rebalancing", others much less. No profile can deal with that issue. There are software fixes for this phenomenon but I've generally found manual correction more satisfactory in these cases. Often finding a good black point and a good gray point is all that's required, perhaps aided with a bit of a saturation and contrast boost.
I did understand from another article that the Silverfast LUTs were not just a replica of the Kodachrome target profile corrections but more adapted to get faster to a good scan result.
On fading I have made my comments already in the other thread. Dark fading must have had little influence so far but projected Kodachrome slides suffered and then with magenta loss. But there were also differences between the Kodachrome 25 <> Kodachrome 64/200 at the time they were all fresh, which goes back to 2001.
met vriendelijke groeten, Ernst Dinkla
New: Spectral plots of +220 inkjet papers:
http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
-
I did understand from another article that the Silverfast LUTs were not just a replica of the Kodachrome target profile corrections but more adapted to get faster to a good scan result.
On fading I have made my comments already in the other thread. Dark fading must have had little influence so far but projected Kodachrome slides suffered and then with magenta loss. But there were also differences between the Kodachrome 25 <> Kodachrome 64/200 at the time they were all fresh, which goes back to 2001.
met vriendelijke groeten, Ernst Dinkla
New: Spectral plots of +220 inkjet papers:
http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
Hi Ernst, yes indeed you did comment on the fading issue in the other thread. Asleep at the switch, I hadn't seen that thread until after I posted in this one.
More generally on the Kodachrome issue, Kodachrome does not have an in-built colour cast for dealing with projection factors. The bluish rendition is the result of how CCDs read the spectrum of Kodachrome dyes. SilverFast deals with this in two ways: partly from the Kodachrome profiles it provides, and partly with other parameter adjustments which are triggered by selecting the "Kodachrome" media in the General tab. Both the profiles and these parameter adjustments are scanner-model specific in SilverFast; but those who make their own scanner profiles will have scanner-specific adjustments at least for the profiling part of the adjustment process. In the specific case of SilverFast IT8 targets and profiles, these are for the DIN ISO 64 version of the film. Presumably that would make them less accurate for scanning ASA 25 Kodachrome (and reaching further back in history ASA 10), but most likely still far better than nothing. Readers may also refer to Figure 14 and surrounding discussion of the benefits of SilverFast's IT8 profiling for Kodachrome in my review of the Plustek 7600iAI film scanner on this website, where I report on both qualities and issues, depending on the scanner model and whether the profile is *canned* or *custom*.
By the way - a bit off-topic, this article http://en.wikipedia.org/wiki/Kodachrome, seems to be very up-to-date insofar as it reports that although the processing of Kodachrome was slated to disappear in December 2010, now in January 2011 Dwaynes is processing a large batch of Kodachrome it received last December.
-
LSI's canned profiles are made PER SCANNER MODEL.
Both the profiles and these parameter adjustments are scanner-model specific in SilverFast;
Mark, how do you know? Can you direct me to the portion of Silverfast’s user’s manual or web page that confirms your statements?
The reason I ask is because the Silverfast profiles I tested clearly were not made for my particular model of scanner and were not scanner specific, nor were the profiles very good.
Also, here is what Silverfast says on their own web site about their Kodachrome profiles: “… we have implemented generic Kodachrome ICC-profiles for many supported film scanners …”. (emphasis added)
-
...Asleep at the switch, I hadn't seen that thread until after I posted in this one.
More generally on the Kodachrome issue, Kodachrome does not have an in-built colour cast for dealing with projection factors. The bluish rendition is the result of how CCDs read the spectrum of Kodachrome dyes...
If you read it I think you will see that proof was provided in that thread that Kodachrome does indeed have a built in color cast (and increased contrast) for dealing with projection factors.
It's possible that the interaction of the scanner CCD, light source, and film dyes will produce an additional blue tendency, but such defects in rendition caused by the hardware are removed (or greatly minimized) by a good scanner profile. The point is that, even after a Kodachrome profile is applied, there is an inherent blue bias due to the characteristic curves of the film itself, that remains to be dealt with by means other than the profile.
It's convenient that Silverfast and other software has a special setting to resolve the problem, but the OP's original question was, why is the special setting even needed?
-
Mark, how do you know? Can you direct me to the portion of Silverfast’s user’s manual or web page that confirms your statements?
The reason I ask is because the Silverfast profiles I tested clearly were not made for my particular model of scanner and were not scanner specific, nor were the profiles very good.
Also, here is what Silverfast says on their own web site about their Kodachrome profiles: “… we have implemented generic Kodachrome ICC-profiles for many supported film scanners …”. (emphasis added)
I wouldn't write this stuff if I didn't know what I'm talking about, be it from research, testing or reliable sources. I don't know what model scanner you have, what version of the program you are using, whether you have all their profiles loaded into your profiles folder where the program can pick them up and whether you have read the profile names of the profiles you tested - pilot error can happen to the best of us. They haven't profiled every scanner on earth, but they've done a large number of them. Clearly if you used a profile not meant for your equipment it may not yield particularly satisfying results. What they call a "generic" profile, means that it is generic to the scanner model in the sense that it isn't a custom profile for the user's particular scanner. I don't see any other way of interpreting that statement in its context.
-
If you read it I think you will see that proof was provided in that thread that Kodachrome does indeed have a built in color cast (and increased contrast) for dealing with projection factors.
It's possible that the interaction of the scanner CCD, light source, and film dyes will produce an additional blue tendency, but such defects in rendition caused by the hardware are removed (or greatly minimized) by a good scanner profile. The point is that, even after a Kodachrome profile is applied, there is an inherent blue bias due to the characteristic curves of the film itself, that remains to be dealt with by means other than the profile.
It's convenient that Silverfast and other software has a special setting to resolve the problem, but the OP's original question was, why is the special setting even needed?
The quote from Hunt is a hypothesis not a proof. That said, even if both factors were true, I think we're agreed that scanners do interpret this film with a blue-ish bias which needs a combination of profiling and other tweaks to neurtralize it.
-
This thread seemed odd to me, and now I think I may know why. Silverfast recently launched its promotion of its “improved Kadachrome workflow.” Now, all of a sudden we have a guy who registers on this web site on January 11, 2011, and the very next day posts a question about scanning Kodachrome. Coincidence? Then, of course, we have the usual promoters of Silverfast extolling the wondrous virtues of Silverfast with posts that read like something straight out of a marketing campaign.
Of course, we’ll probably never know for sure if any of these guys are shills, but the coincidence, if that is what it is, is extraordinary.
-
The quote from Hunt is a hypothesis not a proof. That said, even if both factors were true, I think we're agreed that scanners do interpret this film with a blue-ish bias which needs a combination of profiling and other tweaks to neurtralize it.
Crames, an addendum on this issue, as it has further tweaked my curiosity. I went back to a bunch of Kodachromes from 1959, which I am pleased to observe are remarkably well preserved in terms of colour. So 52 years on....... not bad. Fortunately, we are having a neutral gray day here in Toronto and it is just after noon, so the colour temperature of the light would be about as neutral daylight as mother nature provides. And of course, inside the house I have the usual halogen, incandescent etc. lighting. So I picked-up a number of these images with subject matter making it somewhat easy to detect colour casts. Admittedly, this is visual stuff - no instruments, and not always easy judgments to make; on several of them, I didn't see a blue cast under daylight for which the colours became a whole lot better examined under warmer light, but on some of them I did. So Hunt's hypothesis may have something to it, regardless of other information I've accessed. That said, there's no question the scanner itself plays a major role in how Kodachrome is interpreted - I've determined, for example, that the Epson V750 (CCFL) profiles Kodachrome with better neutrality than I could achieve from the flagship Nikon SC500ED (LED), both using SilverFast's Auto IT8 system and the same target.
-
The quote from Hunt is a hypothesis not a proof. That said, even if both factors were true, I think we're agreed that scanners do interpret this film with a blue-ish bias which needs a combination of profiling and other tweaks to neurtralize it.
Are you referring to the quotes at the bottom of this post? http://www.luminous-landscape.com/forum/index.php?topic=50262.msg415789#msg415789 (http://www.luminous-landscape.com/forum/index.php?topic=50262.msg415789#msg415789)
I don't see that so much as a hypothesis, but more a statement of fact by someone who spent 36 years in the Kodak Research Laboratories, is a pioneer in Color Appearance Models, and one of the more eminent color scientists in the world!
Anyway, if the statement by a Kodak color scientist is not enough, and characteristic curves themselves are not enough proof, I offered a demonstration here http://www.luminous-landscape.com/forum/index.php?topic=50262.msg415697#msg415697 that showed that editing a scan with the same gamma corrections that would serve to align the characteristic curves has the predicted effect of eliminating the blue cast that remains after the application of a Kodachrome profile.
I see in your addendum message below that maybe you are softening your position on this a little, so thanks for taking another look at it.
Cliff
-
Are you referring to the quotes at the bottom of this post? http://www.luminous-landscape.com/forum/index.php?topic=50262.msg415789#msg415789 (http://www.luminous-landscape.com/forum/index.php?topic=50262.msg415789#msg415789)
I don't see that so much as a hypothesis, but more a statement of fact by someone who spent 36 years in the Kodak Research Laboratories, is a pioneer in Color Appearance Models, and one of the more eminent color scientists in the world!
Anyway, if the statement by a Kodak color scientist is not enough, and characteristic curves themselves are not enough proof, I offered a demonstration here http://www.luminous-landscape.com/forum/index.php?topic=50262.msg415697#msg415697 that showed that editing a scan with the same gamma corrections that would serve to align the characteristic curves has the predicted effect of eliminating the blue cast that remains after the application of a Kodachrome profile.
I see in your addendum message below that maybe you are softening your position on this a little, so thanks for taking another look at it.
Cliff
Of course, one always wants to take another look when presented with credible alternative information. Given the history of Dr. Hunt's Kodak research affiliation you mention and the evidence shown, I agree with you that we should take those statements as a definitive explanation of Kodachrome's colour reproduction approach and the reason for it. It does make sense. At the same time, still open are other questions about why Kodachrome behaves better in some scanners than in others using the same software and profiling process. So summing up, we have a clear enough picture now of why Kodachrome is different, the fact that it reacts to scanning differently from other transparency materials and in different scanners, and needs both separate profiles and other tweaks in the scan algorithm to obtain neutral neutrals. It's been an informative discussion. Thank you.
-
I didn't see a blue cast under daylight for which the colours became a whole lot better examined under warmer light, but on some of them I did. So Hunt's hypothesis may have something to it, regardless of other information I've accessed.
Don't know if this is worth anything, but if you look in E-88 (the Kodachrome pdf), on the spectral dye density curves chart, it says, "Normalized dyes to form a visual density of 1.0 for a viewing illuminant of 3200 K."
If you look on any of the Ektachrome pdfs, like E4024 (E100G), the spectral dye density curve chart says, "Normalized Dyes to form a visual neutral density of 1.0 for a viewing illuminant of 5000 K."
Again, not sure if there is any significance there. But it is there.
-
Yes I would think it is significant; looks consistent with the quote from Dr. Hunt.
-
Don't know if this is worth anything, but if you look in E-88 (the Kodachrome pdf), on the spectral dye density curves chart, it says, "Normalized dyes to form a visual density of 1.0 for a viewing illuminant of 3200 K."
If you look on any of the Ektachrome pdfs, like E4024 (E100G), the spectral dye density curve chart says, "Normalized Dyes to form a visual neutral density of 1.0 for a viewing illuminant of 5000 K."
Exactly. Also, for Kodachrome scanning fairly broad-spectrum light sources combined with better Kodachrome dyes matching filters usually result in better scans. LED scanners are not a good match IMHO.
-
Re Dmerger's:
Now, all of a sudden we have a guy who registers on this web site on January 11, 2011, and the very next day posts a question about scanning Kodachrome. Coincidence?
As that statement is a personal reference to me, Guy Burns, 99 Leith Rd, Tasmania, 03 6428 2976 (I never use a pseudonym on any forum/website) I'll let readers decide if my first post was a coincidence. And I should rebut the inference linking me to SilverFast.
In early December 2010, I began the process of slide scanning, with the aim of converting my 3-screen audiovisuals to HD format. It has been a long term aim for about ten years. I have a mob of slides locked up in about a dozen slideshows, produced since 1983. As slides, the shows were presented at a local theatre, but now that I consider digital images to be comparable to slides, my aim is to convert them to HD and use the Barco DP-2000 projector (http://www.barco.com/en/digitalcinema/product/1805) at the theatre to show new digital versions of my audiovisuals.
I assumed the slide scanning would be the easy part. I thought the aesthetic aspect of converting images with a 4.5:1 aspect ratio to 16:9 would be the difficult part. And I was pretty sure that matching the colour and contrast of an image on my monitor to that of the Barco would be quite a challenge. Well, I'm stuck on step one. I still don't know how to scan slides acceptably. As well as using my Coolscan, I'm testing a friend's Plustek, a Canon flatbed, and a Nikon D700. And I'm comparing Vuescan, SilverFast and NikonScan.
One Month Before The Coincidence
Two mates reckoned photographing the images with a Nikon D700, macro lens, barrel and slide attachment was the way to go. Reasonable results now, but it started off poorly. Here's my thread from Dec 12:
http://forums.dpreview.com/forums/read.asp?forum=1021&message=37163593
Three Weeks Before The Coincidence
With the Coolscan, I couldn't understand how it could give such outstanding results for certain slides, results that could not be replicated in Photoshop. Here's my post from Dec 16:
http://forums.adobe.com/thread/766773?tstart=0
Two Days After The Coincidence
I have no connection with SilverFast and I am not enamoured by its capabilities. Initial testing revealed serious flaws in it's handling of infrared dust removal, and it's non-infrared dust removal is woeful (as to be expected). Several articles on Wikipedia reference SilverKeeper, and I've challenged, and am just about to remove, some of them and provide references with more authority (see Stops/Density Range near the bottom of http://en.wikipedia.org/wiki/Talk:Kodachrome)
I want the best digital images from my slides, and at this stage I have no biases. I'm in a pure testing phase which may last several months. I can say, however, that at the moment SilverFast is not high on my list of software. But that might change.
-
Re Dmerger's:
Now, all of a sudden we have a guy who registers on this web site on January 11, 2011, and the very next day posts a question about scanning Kodachrome. Coincidence?
As that statement is a personal reference to me, Guy Burns, 99 Leith Rd, Tasmania, 03 6428 2976 (I never use a pseudonym on any forum/website) I'll let readers decide if my first post was a coincidence. And I should rebut the inference linking me to SilverFast.
Guy...some people wear tin foil over their heads to keep the radio waves from distant planets from taking over their brains...other think black helicopters are coming to get them (truth is, it's the silent drones ya gotta really worry the most about).
So, conspiracy theories abound on the internet...thanks for clearing that bit of theory up...
As I indicated, scanning Kodachrome can be a challenge...the resulting discussion (both the OP and Summary) have been interesting and useful, so thanks for that.
Shills? Really?
Wow...as somebody whose integrity is sometimes called into question I really wonder where some people are coming from. Me thinks he doth protest too much (meaning the weight of the baggage must be immense)!
:~)
Now, back to your regularly scheduled programs...
(Mac vs PC, Nikon vs Canon, Epson vs Canon, DSLR vs MF or ACR vs DPP or Capture NX, etc)
P.S. an apology is in order me thinks...
-
Re Dmerger's:
Now, all of a sudden we have a guy who registers on this web site on January 11, 2011, and the very next day posts a question about scanning Kodachrome. Coincidence?
As that statement is a personal reference to me, Guy Burns, 99 Leith Rd, Tasmania, 03 6428 2976 (I never use a pseudonym on any forum/website) I'll let readers decide if my first post was a coincidence. And I should rebut the inference linking me to SilverFast.
In early December 2010, I began the process of slide scanning, with the aim of converting my 3-screen audiovisuals to HD format. It has been a long term aim for about ten years. I have a mob of slides locked up in about a dozen slideshows, produced since 1983. As slides, the shows were presented at a local theatre, but now that I consider digital images to be comparable to slides, my aim is to convert them to HD and use the Barco DP-2000 projector (http://www.barco.com/en/digitalcinema/product/1805) at the theatre to show new digital versions of my audiovisuals.
....................
I want the best digital images from my slides, and at this stage I have no biases. I'm in a pure testing phase which may last several months. I can say, however, that at the moment SilverFast is not high on my list of software. But that might change.
Guy: Are you on Windows or Mac doing the scanning tests?
-
To paraphrase the African-American woman who complained about the Fat Elvis stamps ("I ain't licking no rear end of no Fat Elvis) -- This slide-scanning beginner don't need no apology, no way. The facts stand.
-
Dear Ernst,
Looking at the specifications of light sources I think HP Scanjet G4050 should be it. "6 Color" mode covers the spectrum of Kodachrome dyes nicely.
-
Re: Guy: Are you on Windows or Mac doing the scanning tests?
G5 iMac, OSX 10.4.11. But my scanning mates who are very keen to convince me that photographing is the best way, are all on PC, so I can access a PC.
Now for a story: I was sitting here testing a few weeks ago, with the scanner in mid-scan, and in walks my D700 mate:
"How long does it take that Nikon to scan a slide?"
"About three minutes, but if you include the preview, a bit of thinking, twiddling, and saving and naming, I'm aiming for 10 an hour once I decide on a process."
"In three minutes, I can do about 30"
Very proud he was, too. I didn't quite know how to respond, but I was very diplomatic as he has some good gear he lets me play with. He's invented a system where he mount slides in a Kodak carousel, sets it to automatic advance (I assume 6 seconds), somehow takes an image from the projector (I'm not sure how he does that yet), sets the camera to take photos every 6 seconds, and away it goes at 10 slides a minute. He's going to charge 50 cents a slide if mounted in a carousel, $1 a slide if he has to brush and mount them. I'm impressed with the engineering, but I'm more interested in quality than speed.
-
Re: Guy: Are you on Windows or Mac doing the scanning tests?
G5 iMac, OSX 10.4.11. But my scanning mates who are very keen to convince me that photographing is the best way, are all on PC, so I can access a PC.
You're fine on a Mac. The only reason I asked is because your comment on SilverFast iSRD didn't jive with my experience using it, and I know it doesn't work with the Nikon Super Coolscan 5000ED on Windows, but it does/is supposed to on Mac.
-
Guy, your explanation has convinced me that my suspicion that you may be a shill was unfounded. I apologize.
-
Guy...some people wear tin foil over their heads to keep the radio waves from distant planets from taking over their brains...other think black helicopters are coming to get them (truth is, it's the silent drones ya gotta really worry the most about).
So, conspiracy theories abound on the internet...thanks for clearing that bit of theory up...
As I indicated, scanning Kodachrome can be a challenge...the resulting discussion (both the OP and Summary) have been interesting and useful, so thanks for that.
Shills? Really?
Wow...as somebody whose integrity is sometimes called into question I really wonder where some people are coming from. Me thinks he doth protest too much (meaning the weight of the baggage must be immense)!
:~)
Now, back to your regularly scheduled programs...
(Mac vs PC, Nikon vs Canon, Epson vs Canon, DSLR vs MF or ACR vs DPP or Capture NX, etc)
P.S. an apology is in order me thinks...
Jeff, please note my apology to Guy.
Your belittling, insulting comment, however, was unnecessary, especially since less than two weeks ago on this web site, when you suspected that someone was a shill, you wrote “Oh well, a putz is a putz...it's fun to kick them when you get them on the ground!” http://www.luminous-landscape.com/forum/index.php?topic=49768.msg413538#msg413538
You didn’t say you suspected them; you convicted and insulted them in a crude manner. You did so based on evidence no more substantial than in the present case. Yes, I said I suspected that Guy was a shill, but I neither convicted him nor did I use crude insults. Under these circumstances, I think your insults toward me reflect a double standard. I suspect that you likely made your insults to me in haste and without sufficient reflection. Perhaps with a little reflection, you’ll reconsider the appropriateness of your comment.
-
Perhaps with a little reflection, you’ll reconsider the appropriateness of your comment.
No, not so much...
You'll notice, even in the context of my post you refer to, I actually ADDED some useful content to the discussion...you? Not so much. You launched into a full scale assault (and didn't limit your target to Guy but implied Mark and perhaps others on LuLa were guilty of being shills).
So, no...I stand by my tin foil and black helicopters post.
And...you'll notice George actually came and joined LuLa (which I think is a good thing).
Your apology is useful...don't ruin it by trying to blame others...
-
Dear Ernst,
Looking at the specifications of light sources I think HP Scanjet G4050 should be it. "6 Color" mode covers the spectrum of Kodachrome dyes nicely.
But does it have the two fluorescent lamps ready for film scanning? Not to mention the usual limited Dynamic Range of flatbed scanners. I was interested in the method, the tests were done on reflective originals only. You have to verify what the specs are for film scanning.
met vriendelijke groeten, Ernst Dinkla
New: Spectral plots of +220 inkjet papers:
http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
-
Don't know if this is worth anything, but if you look in E-88 (the Kodachrome pdf), on the spectral dye density curves chart, it says, "Normalized dyes to form a visual density of 1.0 for a viewing illuminant of 3200 K."
If you look on any of the Ektachrome pdfs, like E4024 (E100G), the spectral dye density curve chart says, "Normalized Dyes to form a visual neutral density of 1.0 for a viewing illuminant of 5000 K."
Again, not sure if there is any significance there. But it is there.
It doesn't say neutral density in one line but I assume that neutral should be there too. If that statement is correct then the two films do not match in projection light (3200K) and one wonders in what light they would match. I doubt any. Seems odd to me though but Ektachrome was of course used in a much wider market than for slide projection only. On the other hand the recommendation has been not to project original Kodachrome slides if the projection time exceeds 1 hour, instead use Ektachrome copies of the original Kodachrome slides. The last must have had a special color correction too then with their different dyes compared to the original, neutrality to 5000K and to be used on 3200K. Scanning Kodachromes can only be a simple task compared to that task.
met vriendelijke groeten, Ernst Dinkla
New: Spectral plots of +220 inkjet papers:
http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
-
But does it have the two fluorescent lamps ready for film scanning? Not to mention the usual limited Dynamic Range of flatbed scanners. I was interested in the method, the tests were done on reflective originals only. You have to verify what the specs are for film scanning.
Dear Ernst,
I remember you mentioned that scanner in one occasion and thought maybe you know. Hopefully next month I will have time to experiment with it.
-
You'll notice, even in the context of my post you refer to, I actually ADDED some useful content to the discussion...you? Not so much. You launched into a full scale assault ...
Your statement is irrelevant to the topic at hand as well as false. You no doubt are aware that this thread is a continuation of another thread that is nearby. I have provided at least as useful content as you have to these threads. I made four substantive posts before the post of which you complain. For example:
Quote from: Schewe on January 12, 2011, 10:31:20 PM
And no, you absolutely need to optimize the tone & color as you scan and not try to fix it after the fact in PS.
Jeff, why?
With consumer desktop scanners, all adjustments in scanning software (other than focus, exposure, ICE, multi-sample and multi-pass) merely edit the pixel data derived from the scanner’s CCD.
For purposes of this discussion, a scanner has two essential parts, a light source and a light sensor; e.g. a cold cathode fluorescent lamp (CCFL) light source and a CCD light sensor. For any scanning software to implement a tone or color adjustment at the scan stage, as I think your comment implies, the scanning software would have to be able to control and adjust (1) the spectral output of the CCFL and/or (2) the way the CCD responds when exposed to light. Scanning software can do neither.
Therefore, since tone and color adjustments just edit the pixel data using typical image editing tools, why do such adjustments absolutely need to be optimized using the scanning software rather than after the fact in PS? In both cases, the adjustments are made after the actual scan.
Some people may prefer to make such “software” adjustments with scanning software. I prefer to make such adjustments using Camera Raw and Photoshop because:
1. With most scanning software, the adjustments are baked into the scan output file, and tweaking these adjustments later requires another scan. In other words, the adjustments are destructive. On the other hand, such adjustments in Camera Raw or PS can be done non-destructively and can easily be tweaked later if necessary.
2. I much prefer the tools and capabilities of Camera Raw and PS to those in VueScan, Silverfast or other scanning software I’ve tried.
Also worth noting are your rather feeble replies to that post. I wonder if my temerity to point out your error has sparked your ire and fueled your need to be so insulting.
And...you'll notice George actually came and joined LuLa (which I think is a good thing).
I don’t understand how this statement is relevant nor do I know the George to whom you refer.
Your apology is useful...don't ruin it by trying to blame others...
Characterizing my reply to you as “trying to blame others” is a complete mischaracterization of what I wrote. Obviously, I was not defending my behavior. I was merely questioning the appropriateness of your use of demeaning, crude insults. Surely, you could have registered your disagreement with what I wrote in a more civil manner. Moreover, deliberating mischaracterizing what I wrote is in itself insulting.
In my immediately preceding post, I tried to be civil and give you a graceful way to reconsider the appropriateness of using demeaning, crude insults. In addition, although your hypocrisy was apparent, I also hoped to give you a graceful way to rectify that error. Sadly, you instead chose to compound your boorish behavior. You recent reply is a collection of irrelevancy, false information and intentional mischaracterization.
Jeff, I was hoping for more from you, but alas hypocrites usually find some way to rationalize their behavior, as you have so amply demonstrated. Moreover, some people have a very difficult time admitting when they are wrong, no matter how obvious. Of note in this regard: when I pointed out the absurdity of your implication that scanning software can implement tone and color adjustments at the scan stage, rather than admit your error, all you would say is: “To be honest, I have very little experience with consumer grade scanners.” So, knowing the tendencies of hypocrites generally, and your aversion to admitting your mistakes, I guess your latest reply is all that I could reasonably expect from you.
-
I wonder if my temerity to point out your error has sparked your ire and fueled your need to be so insulting.
Not at all...I had forgotten that exchange with you so it wasn't a motive on my part. No, what pissed me off was you cross posting multiple times and in the About this Site subforum your specious allegation that a new member was a shill. That's what pissed me off bud...it STILL pisses me off bud.
but alas hypocrites usually find some way to rationalize their behavior, as you have so amply demonstrated.
So, are you the pot or the kettle?
-
Well, Jeff, I can see that our discussion is sinking ever deeper into nonsensical, childish outbursts. I mean, do we really have to debate whether it is appropriate cavalierly to use demeaning, crude insults? In what mature, civil society are such insults ever considered appropriate? It’s surreal that we are even having this debate.
-
I mean, do we really have to debate whether it is appropriate cavalierly to use demeaning, crude insults?
I just thought it was colorful language...and in reality, I had addressed my colorful comments to Guy not you. In fact, I just reread the post you find "demeaning, crude insults" and unless your skin is super thin or non-existant, I still fail to consider them "demeaning, crude insults".
And, again I ask, are you the pot or the kettle?
I ask cause I'm not sure "nonsensical, childish outbursts" is really all that one sided bud. Ask yourself, how do you honestly feel about your recent behavior on the forums? Proud of yourself?
-
Jeff, do you actually expect me to believe that your references to “some people wear tin foil over their heads” and “Me thinks he doth protest too much (meaning the weight of the baggage must be immense)!” are not references to me, but to Guy? And, you expect me to believe that such references are not insulting and that you didn’t intend them to be insults? Your contention is so ludicrous and silly as not to warrant a serious reply.
I see that I should have explained why I wrote that our discussion was sinking into nonsensical, childish outbursts. I’ll try to rectify that error.
When I accused you of hypocrisy, I set out the factual foundation and explained why I thought your behavior was hypocritical. You, on the other hand, resorted to name calling and trite phrases. Such tactics, without foundation, are nonsensical, and the type of tactics you’re likely to see on a playground during an argument between six year old girls.
In my posts I tried to avoid irrelevant accusations, and I endeavored to be truthful. On the other hand, you accused me of not having added “useful content to the discussion”. Your accusation is nonsensical in three respects: (1) it’s irrelevant, (2) it’s false and (3) it takes just a few seconds to review the posts in these threads to show that your accusation is false. I mean, it’s bad enough to lie to make an irrelevant point, but to do so when the truth is so easily discerned, well … that just don’t make a lick of sense. Such a tactic is something I might expect of a child, not a mature person.
You wrote “And...you'll notice George actually came and joined LuLa (which I think is a good thing).” This statement is nonsensical in as much as it’s irrelevant and it’s a complete mystery who is this “George” to whom you refer.
In my posts I did not mischaracterize what you wrote. You, on the other hand, as noted previously, intentionally and quite obviously mischaracterized what I wrote. It is impossible to make sense of such mischaracterizations. Moreover, intentionally mischaracterizing what someone writes or says is another tactic I might expect on a playground, but not in a debate between mature, sensible adults.
Let me make another attempt to put this debate on a more productive course. I’ve already noted where you accused a couple of guys of being shills and calling them “putz”. I did so for a couple of reasons. One was to illustrate your inconsistency. Another reason was that I hoped to awaken some empathy on your part regarding your treatment of others. Perhaps this second aspect wasn’t as apparent as it could have been, so I’ll try again:
Jeff, how would you have reacted if, after you accused these guys of being shills, someone had posted a comment similar to your “tin foil” post directed at me, but it had been directed at you?
If you’re honest with yourself, I think we both know that your response would have been a little less restrained than my reaction to your post, to put it mildly.
Jeff, please indulge me one request: Please don’t react to this post in haste and anger. Let it sit for a few days, or however long it takes for your anger to subside, so you can reevaluate this debate with a little detachment. I really think you’re trying to defend the indefensible, but if after such reevaluation you still feel as you do now, then let’s just agree to disagree.
(By the way, Jeff, my name is “Dean”, not “bud”. However, if you like, you may call me “bud” or Schlitz, or Old Milwaukee. Some of my favorite beers, however, are made by Stone Brewery and Dogfish Head Brewery. Being called ”Stone” might be okay, too, although I’m not so sure about “Dogfish Head”, but it could grow on me. ;))
-
Jeff, how would you have reacted if, after you accused these guys of being shills, someone had posted a comment similar to your “tin foil” post directed at me, but it had been directed at you?
Well "Dean"...
I don't need to wait few days...
I would have engaged in the exact same manner that I have engaged with you. You seem to keep trying to wiggle off the hook "Dean".
You went WAY overboard with your allegation of there being shills on LuLa. Your apology, at a word count of 19 (compared to the Shills in the House? (http://www.luminous-landscape.com/forum/index.php?topic=50428.0) post word count of 182) seems a lot like a newspaper splashing a headline above the fold to sell newspapers and then printing the retraction the next day buried near the classified ads...
The delicious irony in this recent debate with you "Dean" is you STILL don't know who George is...didn't you bother to READ THE FRIGGIN' THREAD you were referring to? I mean, really. It's not that hard. George Jardine now produces video tutorials (which I wrote positively about in that post) and was the source of the question about the two posters with the same IP address. Later in the thread (which I guess you haven't read yet) George Jardine actually signed up for LuLa and made a post (which I thought was pretty cool).
The statement which you claim is "nonsensical" is actually on point if you had read and understood the whole exchange. You quoted me as responding to two posters who happened to have the same IP address (which was indeed later explained) who had glowing praise for George's videos. Did you read and comprehend my post or did you just click on my screen name to see what I've written lately (which I did with you).
The fact that I pounced about the two posters (after Chris mentioned both posters had the exact same IP address) was, I think, based on a slightly higher technical legitimacy than your allegations in "Shills in the House?" don't ya think? So, you try to forget your transgressions by accusing me of being equally as badly behaved? So, since you claim I did something mean and nasty, so it's ok for you have done something mean and nasty?
I don't need to wait days...let's have a poll of the readers, who wins in the "mean and nasty™" category (I suspect I would) and who wins for the outrageous unfounded by any actual facts allegations category?
I think you would win "Dean".
You've been around LuLa a while "Dean" (a year less than I) but I would have thought you might have gotten a little experience posting to forums. You wanna keep giving me grist for the mill? Really? (cool, I'm having fun!)
-
To the other posters in this thread, I apologize for side tracking the useful content of this thread...if "what's his name" quits posting to this thread, I promise to do likewise unless it's actually on topic. Back to you "Dean".
-
Jeff, please note my apology to Guy.
Your belittling, insulting comment, however, was unnecessary ...
Obviously, I was not defending my behavior. I was merely questioning the appropriateness of your use of demeaning, crude insults. Surely, you could have registered your disagreement with what I wrote in a more civil manner.
Jeff, I have not objected to the fact that you criticized my initial post. I have not tried to defend that post. I objected to the manner in which you criticized my post. I objected to your use of demeaning insults.
The only topic of our debate is whether your use of deeming insults is acceptable. I contend that your use of such insults is not appropriate. You contend that your use of such insults is perfectly acceptable. Moreover, over the course of our debate, you continued to use demeaning language and, as you called it, a "mean and nasty™" tone.
I don’t think that much more need be said. You have one point of view about what is acceptable behavior, and I have another. We’ll just have to agree to disagree.
With regard to the specifics of your preceding post to me, I find it extraordinarily irrelevant, childish, hypocritical, and irrational. I think it is readily apparent why I believe so, and I think it would not serve you well, Jeff, nor would it serve any useful purpose, for me to explain why I find your post so. I’m willing to explain my reasons, however, if you think it necessary.
-
The only topic of our debate is whether your use of deeming insults is acceptable.
Uh, you do mean demeaning insults? Right?
With regard to the specifics of your preceding post to me, I find it extraordinarily irrelevant, childish, hypocritical, and irrational.
Well, at least I'm extraordinary...
:~)
The fact is, you still really haven't atoned for YOUR behavior so I'm not inclined to let you off the hook.
In your Shills in the House post you said: "I’ve had a strong suspicion of shills for a long time, but because it’s virtually impossible to prove I’ve not pursued it."
While you've apologized to Guy (in 19 words), you implied that there are other shills lurking here at LuLa. That's an attack on the integrity of everybody here on LuLa. You went on to mention "we have the usual promoters of Silverfast extolling the wondrous virtues of Silverfast" which points the finger at several people. So, ya see, you not only owe an apology to Guy, but to those guys and the rest of the community whose integrity you impugned...
Do you at least know who George is yet?
-
I just found this discussion, so I'm very late coming in with my comments. This may have been covered in previous posts, but with 40 years of Kodachrome experience I thought I would share my experiences. The Kodachrome dye set has a much different infrared transmission profile than that of Ektachrome. When making dupes on Ektachrome Dupe film of Kodachrome originals, the use of a 301 hot mirror was suggested by Koday to suppress excess infrared. The assumption was that a tungsten light source was used to make the dupes. A scanner CCD/CMOS sensor, as well as the light source, would have a much different response.
Rand
-
Jeff, I use your own words to show that you are an immature, irrational, boorish hypocrite and liar, and your number one complaint is ..… I made a typo?
I now realize that I never should have even attempted to engage in a mature, civil discussion with you. Well, it’s over. I’ve made my point; or rather I should say you’ve proved my point with your own words. You can have the last word. You can continue with your irrational rants, but I’ll no longer reply. I’ll no longer wallow in your cesspool. Witnessing your depraved indifference to civility, honesty and hypocrisy makes me feel the need for a long, hot shower to wash away the filth, the slime. So, Jeff, I give you free rein to spew forth your nonsense unchallenged. I’m done. I’m off to take that shower.
-
Jeff, I use your own words to show that you are an immature, irrational, boorish hypocrite and liar, and your number one complaint is ..… I made a typo?
Number one in order but far from the top of the list in importance...that would be looking for an apology to the members of LuLa and those people you alleged were shills.
Have a nice shower, you need it.