The Great Gamma Problem at DVinfo.net

Ben Winter · August 28th, 2011, 11:46 AM

A colorist was looking at our Premiere Pro-rendered ProRes edit in Flame when he noticed the copy was not full-resolution. "No problem!" I said, "I'll just render out a full resolution copy right now. I transferred my Premiere Pro project to FCP by hand and brought it with me." But lo and behold, after export, this copy was different! Its gamma had changed, and thrown off all the coloring as a result. As I had not a copy of Premiere pro, I couldn't render out another copy the same way as the first, and the colorist had to redo everything.

Why is this happening? I notice gamma changes in other places too, for instance when I take a ProRes file into After Effects, then render out to ProRes, I get a brighter gamma shift of about 0.2.

What's going on here, and why is it so difficult to keep gamma consistent?

Andrew Smith · September 1st, 2011, 05:10 PM

There has been a gamma shift bug with Quicktime, but I'm not too familiar with it as I don't use FCP and avoid Quicktime like the plague. Others may have the details.

Andrew

Justin Molush · September 1st, 2011, 05:56 PM

I have noticed this as well - if there is documentation on this as to why it happens, I would be glad to read it...

August 28th, 2011, 11:46 AM	#1
Ben Winter Trustee Join Date: Jun 2005 Location: Hollywood, CA Posts: 1,675 Images: 1	The Great Gamma Problem A colorist was looking at our Premiere Pro-rendered ProRes edit in Flame when he noticed the copy was not full-resolution. "No problem!" I said, "I'll just render out a full resolution copy right now. I transferred my Premiere Pro project to FCP by hand and brought it with me." But lo and behold, after export, this copy was different! Its gamma had changed, and thrown off all the coloring as a result. As I had not a copy of Premiere pro, I couldn't render out another copy the same way as the first, and the colorist had to redo everything. Why is this happening? I notice gamma changes in other places too, for instance when I take a ProRes file into After Effects, then render out to ProRes, I get a brighter gamma shift of about 0.2. What's going on here, and why is it so difficult to keep gamma consistent? __________________ BenWinter.com

September 1st, 2011, 05:10 PM	#2
Andrew Smith Equal Opportunity Offender Join Date: Feb 2009 Location: Brisbane, Australia Posts: 3,064	Re: The Great Gamma Problem There has been a gamma shift bug with Quicktime, but I'm not too familiar with it as I don't use FCP and avoid Quicktime like the plague. Others may have the details. Andrew

September 1st, 2011, 05:56 PM	#3
Justin Molush Major Player Join Date: Jul 2010 Location: Montreal Posts: 388	Re: The Great Gamma Problem I have noticed this as well - if there is documentation on this as to why it happens, I would be glad to read it...