Blackmagic Forum

I just watched a great video from colorist Darren Mostyn on how to use the Film LUTs that ship with DR. It was eye opening and from the comments on that video I'm not the only one who discovered that those LUTs require the input color space to be Cineon! I'm wondering where the input color space requirements for LUTs are documented? I haven't been able to find anything on that.

There's a full chapter on LUTs in the Reference Manual. (p. 2875) That might have the info you're looking for.

This area looks to be undocumented. The Cineon gamma thing was news to me as well. The discussion with Walter Valpatto in the first comment may be of interest to you.

Probable reason is that film emulation luts have the historical/implied connection to film scans, which cineon files and encoding was originally used for. And no-one thought of explicitly specifying this in docs. Hopefully it will be added.

Darren replied to one of my question about this on his video and indicated that, at least with the Film Look LUTs, the beginning of the .cube has comments which indicate the input LUT expectations. It would be great if this was standard across all LUTs!

Here's the top of one of the .cube's for these LUTs

# Resolve Film Look LUT
# Input: Cineon Log
# : floating point data (range 0.0 - 1.0)
# Output: FUJIFILM 3513DI film stock 'look' with D55 White Point
# : floating point data (range 0.0 - 1.0)
# Display: DCI-P3, Gamma 2.6

Jim Simon wrote:There's a full chapter on LUTs in the Reference Manual. (p. 2875) That might have the info you're looking for.

Thanks. Although Chapter 147 covers LUTs, it does not touch upon how to determine the input space requirements. It seems some LUTs have it documented in the .cube if you open it with a text editor, and others you seemingly have to either just know or find the creator of the LUT and ask. Obviously there's an opportunity for improvement in this area.