DNxHD shifting color & contrast at DVinfo.net

Michael Rockmore · March 24th, 2010, 06:41 PM

I transcoded some footage for the first time from H-264 to Quicktime using NDxHD at 10 bit 25fps It all converted quickly and easily however/
The exposure drops about a half stop
The contrast drops and my blacks are no longer black. The picture starts to look muddy.
The color shifts a little to yellow/green cast

I converted the file at all different settings and arrived at the same final result in each case.
The shots before and after were compared side by side in both Quicktime windows and on a CS4 timeline with the same results.

I've now heard reports that this a normal problem that users live with and simply correct.

True or False?

Craig Parkes · March 24th, 2010, 09:10 PM

I would imagine this is a colour space issue. DNxHD is designed to be viewed in a Rec 709 color space, h.264 in a RGB color space. Also if you are working with Quicktimes (i imagine you are?) then that can be an added complication in terms of Quicktime related gamma issues...

Basically, there are a number of interactions going on that make seeing things they way you need to be complicated using your workflow, unfortunately.

Michael Rockmore · March 26th, 2010, 10:19 PM

What's the solution?

March 24th, 2010, 06:41 PM	#1
Michael Rockmore New Boot Join Date: Jan 2010 Location: NYC / West Java Posts: 6	DNxHD shifting color & contrast I transcoded some footage for the first time from H-264 to Quicktime using NDxHD at 10 bit 25fps It all converted quickly and easily however/ The exposure drops about a half stop The contrast drops and my blacks are no longer black. The picture starts to look muddy. The color shifts a little to yellow/green cast I converted the file at all different settings and arrived at the same final result in each case. The shots before and after were compared side by side in both Quicktime windows and on a CS4 timeline with the same results. I've now heard reports that this a normal problem that users live with and simply correct. True or False?

March 24th, 2010, 09:10 PM	#2
Craig Parkes Major Player Join Date: Dec 2006 Location: Auckland, New Zealand Posts: 444	I would imagine this is a colour space issue. DNxHD is designed to be viewed in a Rec 709 color space, h.264 in a RGB color space. Also if you are working with Quicktimes (i imagine you are?) then that can be an added complication in terms of Quicktime related gamma issues... Basically, there are a number of interactions going on that make seeing things they way you need to be complicated using your workflow, unfortunately. __________________ www.afterglow.co.nz

March 26th, 2010, 10:19 PM	#3
Michael Rockmore New Boot Join Date: Jan 2010 Location: NYC / West Java Posts: 6	What's the solution?