How to use Arri Alexa LogC to Rec709.dat in After Effects

[mgr0704]

I have used LUTs before on jobs and it was pretty straightforward, just apply the LUT to the footage, but those LUTs have a .cube extension. I was given this  Arri Alexa LogC to Rec709.dat LUT which After Effects does not recognize. What am I missing here? Thanks.

[Mylenium]

You may need to convert the LUT using a free converter, Resolve or whatever is your preferred color grading tool. The full UI version of Lumetri should also be able to open the file, apply it as a look and from there you could save your own LUT.

Mylenium

[mgr0704]

Hi Mylenium,

Thanks for the quick response.

The LUT came from Davinci Resolve. I am just trying to get the BG plate in the correct color space to add my CGI effects to it. Even if I use the UI version of Lumetri in AE, it does not recognize that .dat file extension. There is an ALEXA_Default_LogC2Rec709 in that Lumetri list of choices that works, but I have a feeling it is probably a .cube file. I don't know enough about Davinci to know if they can just output their color grading settings as a .cube LUT for me. Before I display my ignorance to a client, do you know the answer to that question?

-mike

[Mylenium]

You can generate a LUT from the right-click menus in Resolve, i.e. the viewer with teh active clip or the timeline and you apply them the same way in the bin. Not sure if the changed anything again in recent versions, as my use is just as sporadic as yours likely is. If the file doesn't open at all in there, though, there's a good chance it's borked. The program usually does not complain about anything and will open even the most atrocious files.

Mylenium

[mgr0704]

Thanks.