Trouble ALEXA 35 LUTs

[DonJuan]

Hello all,

I have some ALEXA 35 footage to which I cannot apply ARRI LOOKs properly and I do not know what I am doing wrong. I have watched all the videos, but still cannot figure it out.

https://pasteboard.co/ykgB0thYoO2N.png


This is my color management config. Then, I have downloaded several LUTs from ART (.cube), but when aplying it does some kind of conversion and the highlights go over the top. What am I doing wrong? It is not possible to apply ARRIs Looks to an ACES workflow?

Thank you and apologies for I think this might be a fairly simple question but I am not being able to figure it out. I am fairly new to this area.

[Jan Heugel]

Dear Juan,

please clarify which looks you are using, you are writing "LUTs from ART".
Our Look Library is LogC3/LogC4 only, creative Log-to-Log LUTs from ALEXA 35 are LogC4-to-LogC4 *-cube files, which need a proper DRT LogC4 -> target space;

Thanks,
Jan

[DonJuan]

Dear Juan,

please clarify which looks you are using, you are writing "LUTs from ART".
Our Look Library is LogC3/LogC4 only, creative Log-to-Log LUTs from ALEXA 35 are LogC4-to-LogC4 *-cube files, which need a proper DRT LogC4 -> target space;

Thanks,
Jan

Thanks for answering. I said "from ART" because I downloaded some of them individually, but also tried the pack "Look Library LogC4 3DLuts" and did not work either. Should I use LogC4 on the "Output color space"? When using ACES, what should I use in the ACES output transform?

Thanks in advance.

[Jan Heugel]

Hi Juan,

you are importing LogC4 corretly, but then your're in ACEScct and not in LogC4 anymore, hence you are applying the looks on ACEScct footage, where the look is expecting LogC4.
Plus the look files are optimized for the use of an ARRI LogC4 to e.g. Rec 709 DRT/colorspace conversion.

Best,
Jan