1 Reply Latest reply on Jun 13, 2010 2:15 AM by Simon Bjork

    Working with Linear EXRs in AE - How?

    Simon Bjork

      I've recently been playing around with Linear EXRs (exported from Red footage using RedCineX), but I have some questions about how to work with them in After Effects.

       

      1) As I import the files into AE they look dark, even when I have the interpret as linear light on. If I have it off they look really dark. Which is all correct I guess. But, even with linear light on, how do I go ahead and work with the files. They're too dark for green screen keying for example. My project is set up to 32bpc, Linear, sRGB in CS5. I could use viewing LUTs, but that wouldn't really help with the actual keying for example.

       

      2) How would I go ahead to work with a file that isn't linear to begin with, say for example that my foreground is linear EXR and my background is gamma corrected DPX. They look very different, and I wouldn't want to darken my bg to match my fg. I would guess you'd have to use the color profile converter. Ideas?

       

      3) I tried exporting a LOG file out of RedCineX and converted that to Linear Light using the technique posted on Prolost.com (http://prolost.com/blog/2008/3/15/red-log.html). So if both images are in linear light, they should look the same, right? They don't. The redlog file is still brighter. But log to lin technique tells me to gamma of 1,7 to do the linear light conversion. Should I apply a gamma of 1,7 to the EXRs as well? Feels strange.

       

       

      A lot of questions I know, but I would really appreciate if someone could help me out. I've read everything I could find about Linear Workflow in AE and couldn't find an answer.