Hi
I have an issue with the gamma settings when creating a DCP
I have a scene which is quite dark in the NLE and colour grading but comes out too bright in the DCP. I have tried creating 3 different DCP's with just the one scene using input gamma 2.2, gamma 2.4 and gamma2.6 respectively. I cannot however detect any difference when playing the DCP and I wondered if you could have a look at these DCP's to see if you can detect any differences?
The source files for the DCP are in TIFF RGB 16 bit format/codec
If so let me have a email adress to send to using wetransfer
Thom
GAmma setting
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Carsten
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- Location: Germany
Re: GAmma setting
It may not necessarily be the gamma setting, but could be video range/full range. Some video editing systems allow these two options for export. Depending on export/import pipeline, this may result into either crushed or lifted blacks. Usually it doesn't make sense to export TIFF with anything else than full range. Video/limited range is usually chosen for e.g. MP4 or some other typical video formats - but e.g. Resolve allows to export TIFF with both video and full levels. As far as I know, currently DCP-o-matic has no options to detect this, as it is baked in the data. Don't know wether there are flags to detect this.
- Carsten
- Carsten
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tba
- Posts: 30
- Joined: Mon Jan 15, 2018 4:20 pm
Re: GAmma setting
Yes its full range.
But this is surely an issue which needs to be looked at? Regardless of whatever the input is I assume lowering or raising the input gamma in DOM would affect the final screen brightness, or have I misunderstood this?
But this is surely an issue which needs to be looked at? Regardless of whatever the input is I assume lowering or raising the input gamma in DOM would affect the final screen brightness, or have I misunderstood this?
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Carsten
- Posts: 2665
- Joined: Tue Apr 15, 2014 9:11 pm
- Location: Germany
Re: GAmma setting
You are right, but some signals may show only negligible visual impact with gamma shift.
We should still look into this. Did you really compare these different DCPs with different source gamma settings on a DCI projector?
I may give it a try with a grey step wedge, many can be found on the net.
There is a nice 'free' test chart including a step wedge in 16Bit TIFF format here:
https://www.charbon-studio.com/get/mire ... _scope.tif
DCP-o-matic has a vectorscope under 'Tools' - it should show different gamma settings immediately - and it does for me.
- Carsten
We should still look into this. Did you really compare these different DCPs with different source gamma settings on a DCI projector?
I may give it a try with a grey step wedge, many can be found on the net.
There is a nice 'free' test chart including a step wedge in 16Bit TIFF format here:
https://www.charbon-studio.com/get/mire ... _scope.tif
DCP-o-matic has a vectorscope under 'Tools' - it should show different gamma settings immediately - and it does for me.
- Carsten