SOS export looking much darker than in Avid or original graded RED files...

[James_Mills]

I keep trying different same as source settings and project settings to get a clean export, but it always comes out significantly too dark... am I doing something wrong? And then when I export a H264 setting instead I get the standard greyer and flatter look than I want (it seems to really kill the greens and give everything a greyer look than I want...)

Does anyone know the best settings to have their project at and their export settings to get a duplicate SOS file? Would the best way to preserve this look be to then squeeze it in Sorenson for online streaming?

 

[MichaelP]

You are running into the QuickTime wrapper issues that plague many a folk. QuickTime tries to make things look better by guessing at the codec color space and levels and adjusting for them. Here are a couple of resources to read through. The first one is written by Job TerBurg who contributes to many forums including this one:
http://terburg.home.xs4all.nl/Publications/601_709_RGB.pdf

And this one is an overall explanation of some of the issues:
http://vitrolite.wordpress.com/2010/12/31/quicktime_gamma_bug/


Michael

 

[James_Mills]

Thanks, Michael. Still very much confused though, as I didn't surmise a logical remediation to the issue from those writeups. What does he mean by importing as RGB or 601/709? I didn't know that was an option...?

 

[MichaelP]

Most workflows export a QT reference of the sequence. It is in that stage that you are given a choice of RGB or 709 (which relates to levels more than anything else). Media Composer is an SD/HD system. Meaning that it assumes that media has a black level of 16|16|16 (in 8 bit terms) and a white level of 235|235|235 (in 8 bit terms). While it can work full range, you really need to manage that from the very beginning of the process. If you look at your clips in color correction mode with the waveform/vectorscope you will see where your blacks and whites fall on the scale. For video broadcast, your blackest black would not be below 16. If it was it is bu choice and will most likely be clipped in the process. Assuming you have proper video levels for broadcast and are creating H.264 to be viewed on a computer screen, that uses graphics levels of 0|0|0 - 155|255|255. So if you blackest point is 16 in video world, selecting RGB on export expands black and white point from 16 to 0 and 235 to 255 and everything in between scaling accordingly. Encode from there to H.264.

Michael