-
MC Quicktime Reference Export – Color Issue
When exporting a very large 1:1 MXF file from Media Composer to quicktime reference the color changes dramatically. When exporting 601 the blacks are milky and washed out. When exporting RGB the blacks are crushed way too far and the reds are overpowering. I am sending to QT in order to make a ProRes intermediate for the FCP users on the project. In Avid the file natively looks great. What might be happening on the way to QT that is messing this up? My next option is to try exporting a full size QT from MC but since the original file size is ~400GB, I want to try other options before going this route.
Thanks
Mikael -
2 Replies
-
You are entering the world of the monster known as the quicktime gamma shift. If you just search those three words you will get a heaping of info on the pain involved. I can’t say I ever defeated the beast but found ways of working around it. I would recommend going to a different program than quicktime pro to do the conversions. Sorrenson or Compressor (if it will accept avid ref files) would be the starting place. I have used MPEG streamclip to turn DNxHD files into ProRes before and it worked pretty well, but don’t know about the ref files. Good luck.
Editor / Motion Graphics Artist
http://www.GlenMontgomeryIII.com -
It isn’t a gamma problem, despite the rather popular beleif that it is. In reality, the situation is that the Quicktime codec wrapper is designed for web display. Computer monitors, which are commonly used for web display, use full range RGB. In contrast, broadcast television monitors use a reduced range RGB, commonly called Rec 601/709.
So, what does this mean in practical applications? This means that you have to use the color correction tools in Media Composer to be sure your timeline displays FULL RANGE RGB in the Media Composer waveform monitor. Once you’ve expanded the display( by using the levels or color wheel “master” to IRE 0-255, you can then export to QTRef using the full RGB option. When importing to other applications via QTref files, this will ensure your imports don’t get remapped to Rec601/709 values that result in a washed out looking image.
Reply to this Discussion! Login or Sign Up