Question/Request related to DcamProf

[Ernst Dinkla]

Not on topic in the other thread but in the first messages in that thread the X-rite Dual CC Illuminant feature was discussed. As far as I can judge it the X-rite choice of a halfway adaption to two illuminants profiles could be simulated by developing the image with an illumination profile for each illumination and merge the two results at 50%. I do not see that feature as a necessity either for a raw profile creator but reading the discussion of DcamProf further and the knowledge of everyone involved exposed there, I wonder whether another feature related to dual illuminant could be created. One more aiming at better precision in reproduction work. Suppose you can illuminate an original with two spectrally different light sources after another, make two images, develop them with two different raw profiles but instead of a merge use better algorithms to detect the colorants used and by that refine the color fidelity in the final image. This is not new, I have mentioned it before, the HP G4010 and G4050 desktop scanners relied on that method to reproduce color of colorants beyond the usual photo dyes better. Image Engineering had a test + article comparing more desktop scanners and the HP reproduced acrylic paints better than the other scanners could. The method relies more or less on metameric failure to get that better result. It is the cheap version of multi spectral imaging. Is there a way to get that working in for example RawTherapee or a separate application?

In Dutch this review mentions some details of the HP scanner:
http://nl.hardware.info/reviews/1044/2/hp-scanjet-g4050-review-6-kleuren-technologie


Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
December 2014 update, 700+ inkjet media white spectral plots

[torger]

Although this is very interesting, DCamProf is not so much about reproduction photography. It has the base functionality and could expand into that area but my focus is general-purpose photography, and it's actually quite different. It's very much about hand-tuning tone reproduction and making tradeoffs between conflicting goals. Reproduction photography is quite well-covered already but I've felt general-purpose photography profile makers have been lacking, so there is where I want to contribute.

[Ernst Dinkla]

Although this is very interesting, DCamProf is not so much about reproduction photography. It has the base functionality and could expand into that area but my focus is general-purpose photography, and it's actually quite different. It's very much about hand-tuning tone reproduction and making tradeoffs between conflicting goals. Reproduction photography is quite well-covered already but I've felt general-purpose photography profile makers have been lacking, so there is where I want to contribute.

Anders, thank you for the reply.

It was not that I expected you would undertake yet another task but more that I noticed a competent discussion on raw profiling.

I have my doubts whether reproduction photography is so well covered with suitable tools. Right now I am reproducing some board games of more than a century ago and made by different printers at that time. Before CMYK inks in printing were standardized and most of the prints have spot colors anyway. The CC target is hardly usable for pigments like that, not to mention the variation in brown discoloring of the papers. I wonder whether there are spectral data available of pigments used per time period and location. Could be a nice thesis subject for an art historian /  art restoration student.

Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
December 2014 update, 700+ inkjet media white spectral plots