Blown / Clipped Traffic Lights and Tail Lights on Pocket 4K

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jacobsch

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Blown / Clipped Traffic Lights and Tail Lights on Pocket 4K

PostFri Oct 02, 2020 8:38 pm

Hi there, forgive me if this has been directly addressed before, I searched and couldn't find a fix.

On a recent BMPCC 4K shoot, the sensor was completely overloaded by red traffic lights, burning the light out to basically pure white with nothing really recoverable.

See images below. How can I avoid this mad clipping?

Thanks!

RAW
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(ADMITTEDLY HEAVY) GRADE
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(ADMITTEDLY HEAVY) B&W GRADE
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Dmitry Shijan

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Re: Blown / Clipped Traffic Lights and Tail Lights on Pocket

PostFri Oct 02, 2020 11:34 pm

It is a known red highlights clipping problem in color science gen 4. gen4 color space is not large enough to fit all extreme saturated colors:
viewtopic.php?f=21&t=65149&start=50#p634085
viewtopic.php?f=2&t=82441#p494793
problem was fixed in color science gen 5 in resolve 16.3 beta, but gen5 is still not fully functional and you can operate with it only in with braw tab settings yet.

Another option to fix red channel clipping - "upscale" to redwidegamut color space/log gamma and use red IPP2 LUTs to transform to Rec709.
There is also IPP2 saturation and gamma mapping option in Resolve project settings.
See this workflow for details viewtopic.php?f=21&t=65149&p=543725#p537852

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All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/
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jacobsch

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Re: Blown / Clipped Traffic Lights and Tail Lights on Pocket

PostSat Oct 03, 2020 2:59 pm

You rock Dmitry, thanks will look at all these solutions :-)
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lost_soul

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Re: Blown / Clipped Traffic Lights and Tail Lights on Pocket

PostSat Oct 03, 2020 4:50 pm

Tony Dae has a video that takes a good look at it as well.
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Dmitry Shijan

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Re: Blown / Clipped Traffic Lights and Tail Lights on Pocket

PostSat Oct 03, 2020 11:31 pm

Here are also Gen 4 vs Gen 5 raw only grading vs IPP2 compare:
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All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/
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lost_soul

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Re: Blown / Clipped Traffic Lights and Tail Lights on Pocket

PostMon Oct 05, 2020 7:15 pm

The difference in highlight roll off is like night and day.
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Dmitry Shijan

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Re: Blown / Clipped Traffic Lights and Tail Lights on Pocket

PostMon Oct 12, 2020 4:00 pm

Seems in Resolve 16.3 beta 3 new Gamut Compression option in RAW tab now fix all problems with color clipping in Gen 4 as well as in Gen 5. It just makes Gen4 behave same as Gen5 and protects extreme saturated colors from clipping when you do color and gamma transformations inside RAW tab. This is only for BRAW yet. DNG don't have this option.
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All my custom made accessories for BMMCC/BMMSC now available here https://lavky.com/radioproektor/

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