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Using Magic Lantern => Post-processing Workflow => Topic started by: audiocr381ve on July 08, 2013, 08:01:35 PM

Title: Color changing when brining TIFFS into Quicktime
Post by: audiocr381ve on July 08, 2013, 08:01:35 PM
Hi guys!

I'm having some issues with color when bringing TIFFS from ADR into Quicktime for an Image Sequence.

Here you'll see a shot being edited in ADR and a shot of what it looks like brought into Quicktime. You'll notice that the shots are different but they were exposed exactly the same and shot within seconds of each other, so other than composing the shots differently, they are identical.

(https://dl.dropboxusercontent.com/u/24644882/color-change.jpg)

I'm exporting the footage as ProRes 422 HQ to be edited in FCPX. I checked the footage in FCPX hoping it was Quicktime's previewer that was off and unfortunately it looked exactly the same. Anybody know what's going on?
Title: Re: Color changing when brining TIFFS into Quicktime
Post by: mkorho on July 08, 2013, 10:08:06 PM
Google Search: quicktime gamma
Title: Re: Color changing when brining TIFFS into Quicktime
Post by: audiocr381ve on July 09, 2013, 12:59:50 AM
Gamma was turned OFF. Does it need to be turned on?
Title: Re: Color changing when brining TIFFS into Quicktime
Post by: romeus on July 09, 2013, 02:52:34 AM
There is reduction in contrast and color shift
it's caused by quicktime which converts the luma from  (0-255) to (16-235) and the chrominance to (16-240).now you have a broadcasting color.Prores is Rec.709 color space
try to use x264 encoder it allow to you to select (0-255) full range
http://www003.upp.so-net.ne.jp/mycometg3/
Title: Re: Color changing when brining TIFFS into Quicktime
Post by: deleted.account on July 09, 2013, 06:49:16 AM
Quote from: romeus on July 09, 2013, 02:52:34 AM
There is reduction in contrast and color shift
it's caused by quicktime which converts the luma from  (0-255) to (16-235) and the chrominance to (16-240).now you have a broadcasting color.Prores is Rec.709 color space
try to use x264 encoder it allow to you to select (0-255) full range
http://www003.upp.so-net.ne.jp/mycometg3/

If you go RGB to YCbCr then it should do that mapping, full range in x264 is a bad option unless you can be sure of whole processing back to RGB.

As mentioned the OPs problem is due to wrong gamma and/ or color space in ACR output or using Quicktime on older mac OS than Mountain Lion.

Tiffs can be many color spaces not just RGB so output from ACR needs to be sRGB color space and gamma.

I believe Mountain Lion + latest QT fixes the qt gamma shift issue discussed all over the web.

Can you post a sample tiff and same prores output?