RED-one/Film, LUTs, Color Space Workflow

[bentpixel]

I've just stumbled into some new territory as of late. And I don't really understand certain workflow implications dealing with film-type workflow. So please hold my hand and speak really slow. I'm working on a music video thats been shot on the RED-one camera. My understanding is the RED shoots 12-bit linear. Now the footage that comes is RAW so you have to view it through a lut. Keep in mind we are kind of learning these workflow details as we go. The guys I'm working with gave me the footage as 12-bit DPX files out of a Scratch system. Now they were viewing the footage in Scratch through a HD Rec-709 lut, I pulled up the DPX later on in front of one of the guys in After Effects and the footage looked really dark. He thought something was wrong on the export (ie. something got applied to the footage on export). So I poked around in AE and found HD Rec-709 project settings and applied them and then the footage seemed to be correct. Now is this correct?? I'm pretty new to the idea of luts (I usually just deal with video, NTSC, HD) so am I right path?? Also when I give the composites back should I render out DPXs with any special settings or is there a better way. And I've got some Maya work to do on it so how exactly does this workflow fit into that. Ya I know, I've stepped into some deep mess.

[namekyoyo]

I'm a compositor and scratch colorist and Ive dealt with the issue you are speaking about.

Is you work going back to scratch for color grading? If it is then you will have to be careful about how you apply this rec709 adjustment in after effects to your footage. It is best that you use an adjustment layer in after effects for this. You add your vfx and then when it comes time to render you turn off the rec709 adjustment layer and render out your work. The reason you do not want to bake in the rec709 to your footage is because the colorist in scratch will have a rec709 display lut applied to all his footage....(well that is the assumption) so if you bake in the rec709 adjustment your vfx shots will have two rec 709 adjustments applied to it. One form your render and one from the colorist's display lut. Your fx shots will look messed up.

Again this is assuming the colorist is appyling the rec709 lut.

As for 3d elements..... not sure what to do there. I say you render out a tiff sequence that has the alpha channel of your cgi elements. make the alpha sequence matches the vfx shots and send that to the colorist. This way if the CGI elemets get messed up by luts or anything like that the colorist can fix those elements.

[pingking]

LUT stand for LookUpTable, so it should only affect what you see and not the footage itself. this is also the reason why the Dpx from scratch look to dark without the lut.
i dont know what AE does when you apply the Rec709 settings, but i think i does apply a lut, so you will see the footage in correct colorspace. i hope it doesnt do anything to your files.
so comp your work together with that rec709 settings in AE and send back also 12bit dpx.
better you do a short test with the scratch guys to see if everyhing goes well