projector grading & colorspace riddles

[T. Lavalier]

Hello Everyone,

I hope these questions are interesting not for just beginners.

So, when you grade for film, can one see the whole film color space? Some say film stocks lie inside of DCI, some give various overlap-percentages and then there are these CIE-diagrams where film has significantly more saturation in the cyans and greens. I have even seen graphs that went beyond human vision in the blue, probably UV-direction. This should be easy to determine with the few current stocks?

In general: For the case your viewing-devices can not show the delivery color space, and I assume, at the time before DCI that must have been especially be the case, how is the procedure?

1. calibrate viewing device as close to the target as possible
2. profile device with a CMS
3. create a display(=viewing?-)-LUT
?
and if there is a complete remapping of all out of gamut values, they are gone, even though of course, its a non-destructive viewing-LUT. Is there a re-remapping to the wider delivery-color space? Before there were wides gamut displays and projectors, there where only CRTs. How did you do DI "back" then? Would you use monitoring like the gamut-view of an omnitek xr to compensate for what you can't see on the screen?
Is there even a predictable workflow to grade for film on a rec709-projector for example, without loosing all the saturated colors when printing back? So far, that doesn't make sense to me.

Please enlighten me.

Tom

[Marc Wielage]

I would start by reading the White Papers on LUTs and Digital Intermediates on Filmlight's "Truelight" LUT page:

http://www.filmlight.ltd.uk/resources/documents/truelight/white-papers_tl.php


I would also read the section on monitor calibration in Alexis Van Hurkman's book Color Correction Handbook: Professional Techniques for Video and Cinema (http://www.amazon.com/Color-Correction-Handbook-Professional-Techniques/dp/0321713117/ref=sr_1_2?s=books&ie=UTF8&qid=1330945381&sr=1-2).

This is a very, very complicated area, especially if you're trying to reproduce P3 color space and/or do film outputs. A great deal has to do with what display you're using. There are those who believe that LUTs can be destructive; Michael Cioni makes a good case in his presentation (http://www.youtube.com/watch?v=Qztrb9arZl4) about their workflow on Girl with the Dragon Tatttoo.

Me personally, I wouldn't make a move without hiring somebody who has done this before, has all the right test and set-up gear, and can guarantee the results. I'm told Avical (http://www.avical.com) does pretty good work. Steve Shaw at Light Illusion (http://www.lightillusion.com/) also has another approach, and he's extremely experienced at this (around the world).