Are you saying Kodachrome looks blue because in comparison other slide films are yellowish due to fading? I think that's a stretch!
A scanner profile will preserve the blue cast, not eliminate it. The blue cast is shown in the characteristic curves - would Kodak
publish the characteristic curves of faded film?.
In my previous post I attached 2 images. The first one is the unadjusted scan with a Kodak Q60 Kodachrome target (scarse/argyll) profile
applied. The second one is a simulation of the appearance of the first one when projected, using CIECAM02 to model the changes in viewing
conditions. The difference in appearance is due solely to the difference in viewing conditions.
I agree with Jeff and was only adding additional considerations to what had already been said.
I mentioned several causes for possible flaws in Kodachrome scanning, adding to the ones already mentioned and I didn't suggest that your plots show fading.
Kodachrome has a reputation of not fading starting with the version after roughly 1938. Dark fading that occured affected the yellow dye though. Ektachrome in all its incarnations dark faded faster and mainly on the cyan layer. Kodachrome didn't suffer of yellow staining, Ektachrome does. Both faded in projection on magenta but the Kodachrome much faster. Wilhelm recommended 1 hr maximum exposure for Kodachrome and 2.5 hrs for Ektachrome, Fujichrome 5 hours. Gathered from Wilhelm's book on the permanence etc of color. You will find some of that in the Wiki pages on Kodachrome. http://en.wikipedia.org/wiki/Kodachrome
With the change to digital photography the actual scanning of films today will be more focused on film that has been archived/projected than on fresh film. Kodachrome's use even more shrinking over a longer period. So it is certainly not a stretch.
I do not understand why a Kodachrome slide film should get a blue bias to compensate a yellowish projector lamp and no other slide film needs the same compensation. The same observation is made here:http://www.apug.org/forums/forum40/81778-love-hate-kodachrome-why-all-passion-here.html
Could be corrected on his assumptions of Kodachrome fade resistance though.
What you see as different plots is set in perspective there too, other dyes, other densities, other spectral plots. Kodachrome has a saturated gamut and that will show. More saturation in blue possible which is something else than a blue bias, the last should show in the neutrals. A richer film like Kodachrome will have more deviations on the neutral axis in any display condition as it is harder to control CMY layers, development, lamp aging etc when color contrasts are higher. Profiling in digitalisation can help then but on average not per slide.
There are articles on the Silverfast site on the Kodachrome profiling aspect: http://www.silverfast.com/show/kodachrome-targets/en.html
. Blue is certainly a problem when KC is scanned using an EC profile. See also the scanning part of the wiki Kodachrome page: http://en.wikipedia.org/wiki/Kodachrome
. And yes, Kodachrome gamut should be available then but a blue cast is a flaw in a scan workflow.
With Jeff's remark on different observers you can add an extra difference occuring in this discussion: the Sprintscan's white cool cathode fluorescent lamp versus the LEDs of the Coolscan 5000. I have seen and measured some scanner lights (Eye One, Epson V750 cold cathode. Mirage II cold cathode) and they differ in spectral output. The two types of linear sensors will have (smaller) differences in RGB filters. Jeff's Imacon has a (halogen) tungsten lamp if I recall it correctly (edit: wrong, it looks like 5000K fuorescents are used on Imacons) and most likely a Kodak linear CCD sensor very similar to the one in the Nikon 8000. With all systems tweaked for the chromogenic dyes of Ektachrome-Fujichrome you can expect deviations with Kodachrome dyes.
A RAW export of a 16 bit file to a RAW processor is possible with Vuescan too. There is something to be said for editing in scanner space and 16 bit. Of course the file itself isn't comparable to a Bayer sensor RAW file.
Flatbeds crept into this discussion for other reasons, the Nikon Coolscans, the SprintScan, are of another class.
met vriendelijke groeten, Ernst Dinkla
New: Spectral plots of +220 inkjet papers:http://www.pigment-print.com/spectralplots/spectrumviz_1.htm