Blackmagic Forum

I shot a handful of short clips with a BMPCC 4K in Raw, Raw 3:1, Raw 4:1, ProRes HQ and ProRes 422 to compare file sizes.

As a side project, I underexposed the shots to see how each format responded in post.

I was surprised to see that all three Raw clips had much more noise than the ProRes clips; noise which was only amplified after adding contrast and moving up the offset.

Does the camera apply any noise reduction when shooting ProRes?

It's the only explanation I can think of.

Here are a couple of screenshots to illustrate the difference:

RAW
https://www.dropbox.com/s/n5m9qxhl6za7cao/Screenshot%202018-11-26%2010.53.31.png?dl=0

ProRes HQ
https://www.dropbox.com/s/fzuf7j6qlkt5nc8/Screenshot%202018-11-26%2010.53.21.png?dl=0

This is straight from Blackmagic:

The Pocket Cinema Camera 4K uses our new demosaic algorithm developed with Blackmagic RAW, before encoding to ProRes. This new algorithm helps to reduce noise and improve the dynamic range in ProRes capture. With Cinema DNG RAW, the demosaic is still performed in DaVinci Resolve. That enables full control and manipulation over debayer settings, noise reduction, and highlight recovery to increase the dynamic range measurement beyond that of ProRes.

https://www.cinema5d.com/blackmagic-poc ... on-review/

Thank you very much Sean. That makes perfect sense now.

So what does that mean? That when you import the Raw files into Resolve it cleans up the noise for you? Or do you need to apply NR yourself? Is there a set standard to start at? And what about 3;1 is that less noisy then lossless?

Any help would be great
Cheers

Chris

I can only speak for the UM46P, on which I did extensive tests. DNG is completely untouched, compressed or uncompressed, and shows the most noise. It also showed that digital harshness, which IMHO is partially due to false detail since that camera had no OLPF. I got the Rawlite now, which improved it considerably.

ProRes is filtered, as is BRaw. They show considerably less noise and a tad less detail, but not in an unpleasant way. This is automatically happening in camera or in Resolve and has no settings. Of course, you are free to use additional noise reduction in Resolve if needed.

This is the waveform for the DNG shot:
www.dropbox.com/s/8rc25xcuomj5qf0/Scope ... G.png?dl=0

and here for BRaw in highest quality:
www.dropbox.com/s/wpfl88nk8y78d0i/Scope ... t.png?dl=0

Coming from the camera, noise reduction is greater in ProRes but noticeably reduced in BRAW and absent in lossless raw, but I would think compressed raw has some as a byproduct of the compression.


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I have to do green screen and I wonder,
Is i better to use the prores (with less noise if i understand you right) but in 10 bit, or the Braw with more noise but a 12 bits color deph ??
Or should I use the Braw and denoise all my footage befor using them ? (maybe the best but too long)