color/raw workflow in resolve 15 (free)

Started by codemonkey, July 11, 2019, 09:18:33 PM

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KirbyLikes525

Quote from: masc on July 13, 2019, 11:14:40 AM
RAW data is data captured from the sensor before any processing. ProRes is processed and lossy compressed data. 10bit RAW includes more usable data than 10bit ProRes. If one force converts with wrong parameters (e.g. wrong WB), one looses important data forever. So having recorded RAW before is nearly useless. ProRes is nothing bad, if used the right way. If mp3 is good for you and diskspace is another problem... why not recording H.264 and converting to ProRes ;D Has nearly the same effect but is much easier.

I think we tried to explain it often enough now...

I agree with most of that. And to anyone that has a cDNG workflow nailed down, I'm not trying to talk them out of it. But since the OP already had ProRes in the workflow I shared my .02
5D Mark II
10 bit 12 bit Experimental Build

reddeercity

If doing a ProRes work flow , You should be using Apple ProRes 4444XQ it's the only one that will keep the full range of color as it's a Full range Codec (0-255)
in either linear, (Rec709 , 16-235 & 0-255)  or 2020 color space . Ffmpeg ProRes is not as good , best you will get is 10bit 444 rec709 that will clip your colors .
I've have notice too with ffmpeg the file is not as clean as apple prores , I've compared them both .
If you are cutting prores files in FCPX , it will build all your proxy for you on import on the fly and by toggling off the proxies files your back to your Original files .
My 2 cents

masc

Yepp, color is better when exporting with AVFoundation ProRes 4444. On the other side, if you have to stretch/resize the footage, AVFoundation is not able to do it and doing it in FCPX looks worse than with ffmpeg. So you'll have to decide between color vs. sharpness. ;)
5D3.113 | EOSM.202

ilia3101

I really wanna see a comparison, sounds so weird to me that colours are better with apple encoder. There must be a way to configure ffmpeg to be equal if it is not.

Danne

Quote from: Ilia3101 on July 19, 2019, 12:25:08 AM
I really wanna see a comparison, sounds so weird to me that colours are better with apple encoder. There must be a way to configure ffmpeg to be equal if it is not.
+1, too many misconceptions around this.

Luther

I know I'm beating a dead horse, but I'll (try) to contribute to the discussion anyway.

Quote from: KirbyLikes525 on July 12, 2019, 08:10:13 PM
No one touches color, including WB, before the colorists which is typically after editing and the media is already in a 10 bit ProRes/DNxHD(R)/MXF file.

You're wrong in this part @KirbyLikes525. In high-end movies color grading is not done in ProRes or other intermediate codec.
Maybe in television shows it is, because it's a faster workflow.
The process goes somewhat like this:

Raw > Convesion to OpenEXR > CG > Color grading > ProRes > Distribution format (H.264/H.265)

The Raw conversion already fixes some issues: white-balance, normalise exposure, high quality debayering, lens profiles (fix distortion, CA, etc), sometimes denoise (new algorithms work before even debayering), color space (normally ALEXA Wide Gamut or ACES AP1) and curves (normally Log-C or ACEScct).
This then it is rendered to OpenEXR for other post-processing (CG, montage and audio processing) and then, finally, into the color grading guy.
It's important to note camera white balance is most times wrong even if you use gray card, because debayering will affect how color is interpreted. I noticed this on MLV too, not sure this is a significant variation in high-end cameras such as Arri.

The correct term for ProRes should be "visually losless", not "virtually". For the human eye, no one will be able to perceive a difference between ProRes or true lossless (considering the bit depth and color space is adequate to the display where it is playing). But, for color grading, there's other variables that ProRes cannot contain and are important for processing, such as independence of color spaces (not something compressed like Rec.709) and bigger dynamic range.

Quote from: masc on July 13, 2019, 11:14:40 AM
So having recorded RAW before is nearly useless. ProRes is nothing bad, if used the right way. If mp3 is good for you and diskspace is another problem... why not recording H.264 and converting to ProRes ;D Has nearly the same effect but is much easier.

It's not useless @masc. The processor inside those cameras cannot do complex debayering like we have in MLVApp (AMaZE) in realtime. You know that much better than me, you're the primary developer of mlvapp. Those cameras cannot contain a high powered GPU/Manycore processor because it consumes too much power and heats too easily...
Maybe OpenPiton will solve it :D

masc

Quote from: Luther on July 19, 2019, 03:15:57 AM
It's not useless @masc. The processor inside those cameras cannot do complex debayering like we have in MLVApp (AMaZE) in realtime. You know that much better than me, you're the primary developer of mlvapp.
This is indeed absolutely right. But the discussion was more about color up to my post.

Quote from: Ilia3101 on July 19, 2019, 12:25:08 AM
I really wanna see a comparison, sounds so weird to me that colours are better with apple encoder. There must be a way to configure ffmpeg to be equal if it is not.
The most differences are on saturated green and pink..red tones. Just render a clip twice (AV+ffmpeg) and compare. If it is just bt709 vs bt2020: this is solvable in ffmpeg. The difference is very small!!! On the other side: AVFoundation encodes with 12bit and ffmpeg with 10bit... but hey: if MLVApp is the last grading step, even 8bit would be enough.
5D3.113 | EOSM.202

togg

Quote from: codemonkey on July 12, 2019, 10:50:59 AM
thanks for pointing that out.  i wanted to stay in raw in resolve, but there's no way around that when i shot in hdr. 

is there an easier way to automatically adjust white balance in mlvapp with with a colorpicker thing with a white

is there something better than prores4444 for editing in resolve?

to get back to the original question.

There're multiple possibles workflow for grading in Resolve, the key is to not work directly on REC709 data structure.

In my worflow I export dng from MLVApp, than do some basic correction on Raw panel inside Resolve to get the same starting look:


- bmd film input on raw panel to BMCC v2 rec709 as output lut

+2 exposure on raw panel
-20 saturation on raw panel   (testing on other images brought this to -10 sat)
+20 contrast on raw panel


I prefer to grade inbetween the bmd film input and the rec709 output. But if you can't bring dngs to Davinci because of hdr (I don't know how that works) try export the bmd ProRes from MLVApp, as far as I have understood it only has the real bmd gamma and not the real bmd gamut, but give it a shoot. try the output lut for BMCC v2 as I do and grade in between.