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Blackmagic - crushed blacks


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#1 David Schmüdde

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Posted 03 September 2014 - 08:29 AM

Hello everyone, I'm not getting what I expect to see from my raw file. I suspected it was a colorspace issue, but I don't see any other people having the same problem. Here are two still photos, from the exact same night, with the exact same settings.
 
Prores looks as I expected it:
 
prores.png
 
Raw looks to have a color temperature issue (no problem). Even worse, it is grainy and the blacks are crushed. 
 
raw.png
 
I take it into Resolve and there just isn't much information in the black. It’s about a stop and a half under exposed at 1600, but that’s the amount of light we could afford to rent. I thought I may be looking at it in the wrong colorspace but I’m seeing no indication. Any ideas?
 
Thanks,
Schmuüdde

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#2 David Mullen ASC

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Posted 03 September 2014 - 09:22 AM

Looks like it has been double-LUT'ed by mistake, a Rec.709 LUT on top of Rec.709
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#3 Will Montgomery

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Posted 03 September 2014 - 10:41 AM

David's right, in Resolve it's easy to accidentally do this...the LUT can be applied in several places that allows for a doubled LUT. I'm not an expert but check the footage in the media pool and then in the timeline; LUT's can be applied in both places and you only want it one.


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#4 David Schmüdde

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Posted 03 September 2014 - 10:57 AM

That's just the tip I needed. I've never shot with a Blackmagic and was unfamiliar with "BMD Film". It was indeed double Rec.709'd. I viewed the sequence as BMD Film instead and that image aligned with my expectations. 

 

You're brilliant, thank you.

 

Edit: 

 

Oh, and Will, just saw your post -- that's exactly what it was. Thanks!


Edited by David Schmüdde, 03 September 2014 - 10:58 AM.

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#5 David Mullen ASC

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Posted 03 September 2014 - 11:03 AM

I've seen them make that mistake in some of the top D.I. suites in Hollywood so don't feel stupid...
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Metropolis Post

Wooden Camera

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Media Blackout - Custom Cables and AKS

The Slider

Rig Wheels Passport

Paralinx LLC

Ritter Battery

Visual Products

Technodolly

Abel Cine