Gamma Shift?

Question

Level 1

2 points

Gamma Shift?

I am having a problem when I export a clip from FCP 6.0.4, there is a pretty significant shift in color. Maybe it is a gamma shift? The exported clip is much lighter, it has less contrast. The problem started when I installed Snow Leopard. My monitor is a Dell UltraSharp 3007WFP-HC 30-inch. Below is my work flow on most projects.

1. Shoot RedOne
2. Compress footage with RedCine to ProRes HQ
3. Edit FCP 6.0.4
4. Color Correct in Color and send back to FCP
5. Export clip from FCP using "Export Quicktime Movie..."

I have color calibrated my monitor with the Spyder3 Pro. I also tried changing rendering setting in the Video Processing tab of the Sequence Settings. Neither of those worked.

The only thing that seems to work is changing the color calibration to a preset, Apple RGB, but this makes my monitor very dark and all of my color correction appears too light on other monitors. I understand that an LCD is not the best option for color correction but I don't have another option right now.

Mac Pro 8Core 3.0 Intel Xeon, Mac OS X (10.6.2)

Posted on Dec 12, 2009 12:21 PM

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Answer 1

Dec 12, 2009 12:43 PM in response to JJBad

How are you monitoring the exported qt movie? In what viewer?

Jerry

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Answer 2

JJBad Author

Level 1

2 points

Dec 12, 2009 12:51 PM in response to Jerry Hofmann

Quicktime X, is that what you are asking? Quicktime 7 is more accurate but unfortunately that doesn't help too much since I need the clip to look nice on as many other machines as possible. I did just try and export using Quicktime Conversion and it appears to be better, still not the same as FCP but better.

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Answer 3

Dec 12, 2009 12:53 PM in response to JJBad

What is your intended delivery? Some sort of web stream then?

Jerry

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Answer 4

JJBad Author

Level 1

2 points

Dec 12, 2009 4:41 PM in response to Jerry Hofmann

Yes it will be for the Web.

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Answer 5

JJBad Author

Level 1

2 points

Dec 14, 2009 4:04 AM in response to JJBad

Anyone????

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Answer 6

Dec 14, 2009 4:24 AM in response to JJBad

I posted this in another thread:

+What your seeing is a gamma shift in Quicktime. This especially happens when viewing h.264 videos on a Mac with Quicktime. Here read this:+

http://ahrengot.wordpress.com/category/tips-and-tutorials/

+I just started using x264 to encode my h.264 videos. As for now I've been happy with it's results. This x264 codec is (a lot) faster than encoding h.264 with Compressor or Quicktime. MyComet x264 encoder has been an in development for mmmm...4-5 years. So it's not a fly by night project. Updates come very fast....too.+

http://www.apple.com/downloads/macosx/video/x264encoder.html

Hope this helps.

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Answer 7

Samboway

Level 1

24 points

Dec 14, 2009 6:02 AM in response to David M Brewer

One other thing to bear in mind is that I believe that all Pro Res codecs are gamma 2.2 not 1.8. I'm not sure whether this may help or not but in Snow Leopard Apple have set the mac's default and QT X as well I believe to have their Gamma at 2.2, whereas all OSX systems before have been at 1.8. As Pro Res is a 2.2 Gamma codec that may cause the shift when viewing it back in older versions of Quicktime.

http://documentation.apple.com/en/finalcutpro/professionalformatsandworkflows/in dex.html#chapter=10%26section=8

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Answer 8

JJBad Author

Level 1

2 points

Dec 14, 2009 6:40 AM in response to Samboway

Right. Which seems bizarre to me since I am viewing the Pro Res codec in QT X and it is a different color than what it appears in FCP. I figured it should be the same for that reason.

Here is an new observation. Not sure why I didn't check before. But I just viewed the capture scratch and the ProRes clips are much lighter colored than after I drop them in FCP, Color, or as I exported them in RedCine. And the ProRes clips are consistently the same color in QT X and QT 7. It is only h.264 that is different in QT X and QT 7.

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Answer 9

JJBad Author

Level 1

2 points

Dec 14, 2009 6:45 AM in response to David M Brewer

I'll check this out

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Answer 10

Dec 14, 2009 8:44 AM in response to JJBad

Yo dude. H264 will always seem to Gamma shift depending on the different players. I have yet to find a good solution to this other than color a specific version to be delivered via H264. There are one or two things I need to check into but will get back with you ASAP.

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