Exporting VFX from RED RAW from After Effects
I'm having a problem.
We have shot a shortmovie on RED and are adding some VFX to the shots in After effects. After that, we are planning on grading the finished material on Nukoda.
Now for my understanding and workflow:
We added the RED RAW directly to AE, added our effects and planning on exporting the material now to 10bit DPXlog sequences, to bring them into Nukoda and go through the grading with the full range we can access with RAW.
But what do I have to keep in mind when exporting?
1) I've read I have to interprete my Raw footage to log, right?
2) When I add the VFX, what do I have to keep in mind? To sell the composite effect, the added effects have to have the same log-look my material has now, right?
3) What do I have to set up when exporting? Do I need a color profile, or do I just start to export DPX sequences in 16bit? What about this checkbox at the DPX-settings "logarithmic conversion"? What is this about?
I am a little worried that we export all our material and we cannot access the whole range at grading anymore.
Can you help me out with this?
Best from Germany,
Red or film footage it is preferable to work in 32 bit linear for all compositing. You *do not* want to work in "Log" space.
You will only convert to LOG DPX sequence if that is what the DI house wants - but that is an export issue, not a working space issue.
FIRST: let's clear up a misconception - what is "LOG" space really? It is actually a LINEAR encoding of FILM DENSITY - but guess what? Film density is log - therefore, we are used to talking about film footage in 10 bit DPX as "log"., or put another way, the gamma curve is "log" - interestingly, the gamma curve for regular video is actually quite similar to log - and it is technically incorrect to call regular video with a gamma curve "linear".
"Lin" or Linear means a "straight line", also known as "Gamma 1.0". "Vid" or Video typically means with a particular gamma curve applied - and that gamma curve will vary depending on the color space used.
Stu discusses this at length:
But to sum:
Vid: Implies a gamma encoded image file.
Lin: implies an image file with no gamma (aka Gamma 1.0)
Log: Implies an image file encoded with film densities, i.e. a gamma that evaluates as film densities.
So what you want to do is bring in your RED footage to an AE project that is set to 32-bit linear, and pick a colorspace for working - in most cases I suggest sRGB when working in linear space, though there are reasons to work in a larger space at times, in *most cases*, a working space of Linear (gamma 1.0) sRGB is preferable, particularly if you are going to end up in Rec709 (HD) space.
If you are going to output to film or to Digital Cinema, a case can be made for working in a larger space like Adobe 98 or DCI/P3 (particularly if you have a true wide gamut display that is properly calibrated). I do suggest that you avoid working in any of the really large spaces like "ProPhoto" however.
When you do your compositing in AE (or Nuke) using linear space, then when you ADD, you will be adding images the same way that lights add in real life (that is, real light is linear).
Set your comps to *Use Display Color Management" Under the "VIEW" menu.
When you EXPORT, you can use the Cineon converter method, or use the "Universal FIlm Profile". You should discuss with your DI house what specs they want for the show. If you use the Cineon converter method, one common setting when *coming from a linearized workspace* is:
"Gamma 1.0" is the same as saying "Linear working space".
The "Log Convert" checkbox will then convert to log space.
Use your working space for your color profile in most cases here.
If you use the "Universal Film Profile", it takes care of the Cineon/log conversion for you.
Correct me if I'm shooting myself in the foot here, but one of my colourists who likes to receive final DPX sequences in "REDlogFilm" seems to like this workflow:
I Work in R3D raw in a linear space. When you are finished with your effects work, simply:
1) go to the project panel and interpret all red footage (Ctrl+Alt+G) then on the popup (in AE CC 2014 anyway and with RedCineX-Pro installed):
2) you will see a [More Options…] button at the bottom. Click it and you’ll see:
3) the RED source settings. Here, change the Gamma Curve to: REDlogFilm (From RedGamma4 or whatever it is) and click OK. Then:
4) when exporting DPX sequences use the Preset “Full Range” and uncheck Logarithmic Conversion and use units: 16-bpc (10 bit Depth)
Seems to work very well for us, but if I'm missing something, please let me know.