Using DPX LOG files with custom LUT? Help!

[michaeld15147761]

Hi there, I work at an animation studio. I need to import DPX files that are rendered in LOG color, convert them to LIN color, and add a custom LUT - all so that I can work on those files, do my effects/mograph, then ideally export back out DPX files that look the same as the ones I imported. Any thoughts on how to do this?

The custom LUT I've been given is a .cube file, and the "Apply Color LUT" effect doesn't want to read it. I also found the OpenColorIO plug-on online, but haven't gotten that to work yet - I may have some success if I play with it some more.

Any help would be appreciated! Thanks.

[Jose Panadero]

Try to add the color finesse plug-in in the Syntetic Aperture category into your footage and apply the LUT inside color Finesse to check if the .cube file is correct.

Another option is to install the free version of DaVinci Resolve to create a LUT based on the one you have, and export a LUT using another format for using the Apply Color LUT effect

[Mike_Abbott]

You should be able to apply your .cube LUT through the Effects > Lumetri Colour effect : Basic correction tab > Input LUT...

However, I'd strongly recommend you read the content in the following thread

FAQ: Where can I find out info about the Lumetri Color panel?

- particularly the last thread that Kevin links - "Lumetri Color Explained"

[chrisw44157881 · Accepted solution]

i'd use opencolorio:

1. apply above video for log to lin

2. composite in linear sRGB, then apply monitor specific calibration as guide layer(as it won't render out)

3. above all effects, adjustment layer, convert lin back to log

4. render out log again in DPX or EXR

this keeps you from rendering out your own monitor calibrations and has high quality

log to lin conversions without color management which otherwise loses 0.1% quality.

http://fnordware.blogspot.com/2012/05/opencolorio-for-after-effects.html

your lut is probably a LMT.

also, in Ae, enable blend colors using 1.0 gamma for matching linear color compositing rules.

you can use apply lut if you download the manufactor's lut generators. same concept for

sandwiching effects and preview guide layer inside log to lin layers.

I wouldn't use the apply lut effects or lumetri except as preview luts as they are limited to sRGB color and could cause banding in higher color models like ACES.

[Kevin-Monahan]

Which workflow did you end up using, Michael D? Your answer might help others looking for the same solution.

Thanks,

Kevin

[michaeld15147761]

Hi Kevin, thanks for following up. I ended up using OpenColorIO, as @chrisw44157881 mentioned above.

I actually ended up making a how-to guide which details how to get your DPX's to look correct in a standard (eg: sRGB) workflow, as well as how to make any AE graphics look ungraded, so they can be comped onto the DPXs and re-exported.

Here's a Dropbox link to my process doc, as there doesn't seem to be a way to attach files. It was created for our internal use - I've modified it slightly to remove some of our specific info:

Dropbox - DPX to AE process-Nov2017-external.pdf

Cheers,

Mike