Hi all!
I have recieved some DPX-files and when I use "auto-detect" for the colorspace in the Read-node it assumes it to be in sRGB. I had some other files laying around so I tested them, and I noticed some were converted from "cineon" and some from "sRGB".
After some digging in the DPX header I found that the files that were assumed to be in sRGB-space had a Transfer characteristics value (offset 801 in the DPX-header) of 2, meaning "linear". The good ones had the value of 1, meaning "Printing density" (which Nuke uses the "cineon"-curve on).
I got a hunch that many applications does not fill in those fields correctly. For instance, those file I have is supposed to be logaritmic, NOT linear. So it's wrong in the header to start with. Nuke seems to do the wrong thing on top of that and say it's in sRGB color space. Arrh... (Ok, who would send a 10bit LINEAR file anyway?)
Does anyone has experience with these things? Any recommendations on how to handle incoming files (other than having a Northlight in your facility and scan the film yourself 
Cheers!
/H
