Export to DNxHD 444 Gamma problems

[David Roth weiss]

Your post is confusing… You’ve told us what you shot and what you delivered to the colorist, and what you want to export, but what has your colorist delivered to you? Has he delivered a graded master to you that you’re using now for your additional exports? Please connect the dots for us telling us where the colorist fits in to your workflow? You seem to have left that out?

David Roth Weiss
Director/Editor/Colorist & Workflow Consultant
David Weiss Productions
Los Angeles

David is a Creative COW contributing editor and a forum host of the Apple Final Cut Pro forum.

[Joseph Owens]

[Josh Williams] “Data levels – video

Colour managment
rec 709 scene
“
and
“DNxHD 444”

….need to be handled with care. Most 4:4:4 codecs are really there for RGB full-range operations. ProRes444 is also notorious for this kind of reported error because the NLEs do not have a mechanism for detecting the appropriate video level black-white range automatically. When you cite “washed out, too dark”, its a red flag. Gamma issues are usually blamed, but that should really be a thing of the past, when the RGB –Y’CbCr range issue is a much bigger problem. In the end, this is a measurable, quantifiable technical problem and you can approach it simply by running a test with a calibration signal like color bars and a scope. Analogically, you are the pilot on final who thinks you’re coming in a little bit off the glideslope, and I’m the controller who is asking you what your altimeter reads. You have one. Most modern aircraft also have a glideslope indicator, but that’s another thing.

jPo, CSI

“I always pass on free advice — its never of any use to me” Oscar Wilde.

[Glenn Sakatch]

what joe said…. get your colorist to put bars at the head of his output. Look at that on the scopes of what ever you are bringing it back into.

Does your colorist have a calibrated screen? Is he using scopes? you said he is inexperienced…look at his scopes on the shots that are too dark, or too washed out…how do they look on his scopes? Is he crushing the blacks, but his screen looks ok? (or vice versa?)

Glenn

[Josh Williams]

Its to deliver to a company for QC, they will then be uploading to youtube.

I read something about vimeo and youtube recognising and adjusting for the video levels. I have just done a couple of tests uploading the file and it has darkened down again but there is a bit more magenta coming out now.

I gave the colorist the files and he graded with resolve. I am just helping to get the export settings right (he has been giving me resolve files and we have both been trying different export settings), as when we exported it seemed to look wrong.