LUT problem (using RAW-Video & DaVinci Resolve 11 Lite)

[EVZML]

Hello.
I have a problem using the Osiris LUTs by VisionColor.
I used Osiris LUTs many times with standard H.264 videos, mostly the M31 LUT. But since I got my Canon 50D and DaVinci Resolve, I can not work with these LUTs anymore, because they doesn't look good anymore (noisy+too much contrast). I think I do something wrong in my workflow.

So here is my workflow:

-Shooting video on Canon EOS 50D in RAW-Video, not MLV! (using KomputerBay CF 64GB 1050x, resolution:1568x882, 24fps)
-Converting .RAW files via rawcdng 1.5.0.BETA6 (CDNG 16bit, nothing else selected)
-importing folders including .dng files into DaVinci Resolve 11 LITE (on Windows 7 64bit)
-DaVinci Resolve Camera Raw Master Settings: Decode using: Clip / Color space: BMD Film / Gamme: BMD Film
-DaVinci Resolve Settings->Lookup Tables: 3D Input Lookup Table = BMDFilm to VisionLOG-RAW 3D LUT_64
-DaVinci Resolve Settings->Lookup Tables: 3D Output Lookup Table = M31 (LOG)


Even with good lighting setup, my video files get too much noise, plus the video files have too much contrast and saturation. Looks like I would have applied the LUT 3 times over the video or something like that.
I hope somebody can help me, so I can work with my soo much loved VisionColor Osiris LUTs, like back in the days where I was shooting H.264 

PS: Magic Lantern RAW videos are 14bit, right? So why does rawcdng just have 12bit or 16bit output?

[dyfid]

Are you starting from a clean template that you've set up for raw, no hidden track node luts applied.

Have you satisfied yourself that your primary corrections on the raw files give you  a good starting point to do your LUT ***kery after. Using the scopes as a guide.

Then apply your input lut and check scopes and preview, then apply your output LUT and look at scopes again.

Maybe step away from following some crib sheet approach and hope you don't mind but learn how to use Resolve a bit better, relying on these look LUTs is so limiting and doesn't help when problems arise.

[swinxx]

in my experience its better to use the bmd4k profile.

however, the bmdfilm to visioncolor lut is not meant to be used with canon raw material, but blackmagic cameras.. so perhaps you could try to kick it out of your workflow.. ?
does it look better than..?
can you post some screens with only the bmd film profile applied and with all the luts applied..

greet.s

[EVZML]

Hey. Thanks for the fast reply!
I recorded some test footage, in RAW and in H.264, so you can see what I mean.

@dyfid: Yes, clean template. Maybe you're right, but I'm always like learning by doing   

@swinxx: I read somewhere else here in the forum, that I need this bmdfilm to visioncolor profile.
The problem is, when I don't use this bmdfilm to visioncolor lut (means just use M31 LOG LUT), I get a very dark image!
See screenshots...



And you right, I can see a little difference in this bmdfilm4k! 


EDIT: VisionColor Website says, I need a "VisionLOG" Conversion profile and the LOG version of the LUT, when using Magic Lantern. Isn't this the "bmdfilm to visioncolor" lut?
Look at the bottom of this link: http://www.vision-color.com/osiris/

[dyfid]

Hey. Thanks for the fast reply!
I recorded some test footage, in RAW and in H.264, so you can see what I mean.

@dyfid: Yes, clean template. Maybe you're right, but I'm always like learning by doing   

Yes me too, best way.

I've not used all these LUTs but if the h264 to whatever LUT looks right to you, like the bottom image then Rec709 for colour space and gamma would seem the choice, that's what your h264 is using Rec709 primaries & Rec709 transfer curve.

To me using BMD colour space and gamma for ML raw -> final output in Resolve is pointless, no point using a logish transform for raw because you have full control over shadows, highlights, lift, contrast all within the raw tab.

Every intermediate this 3D LUT to log to that 3D LUT when working with raw to me is ***kery. Introducing interpolated error. If you start with flat or log source out of the camera then fair enough work log but with raw what is the point?

Try Rec709 colour space and gamma in your raw tab, apply your M31 whatever look LUT to your Output and tweak your raw settings mentioned above which will affect the raw data under your M31 LUT until you like what you see. Closer to your h264 -> M31 workflow previously.

[goran]

In this thread I started some time ago I'm addressing exactly the problems you're facing. Read it for the workflow that works best in my opinion with raw footage and the Osiris LUTs.

http://www.magiclantern.fm/forum/index.php?topic=12340.0

[baldavenger]

I'm coming round to dyfid's way of thinking on this.  My initial concern was the apparent limitations of the Rec709 colour space, and like most I'm reluctant to compromise any image quality therefore the expanded gamut BMD Film appeared to be a better choice, without necessarily knowing exactly what any of that in fact means.

However, considering the initial access to RAW data and 32bit floating point (so no clipping) then perhaps that's unnecessary?  3D LUTS are destructive so surely they should be avoided unless entirely necessary?  I know Peter Doyle refuses to use them so that's worth considering.  I'd love a definitive explanation on all this as I have a project coming up and I've yet to decide my final workflow approach.  I'd really like to know the best and cleanest way to emulate film stocks.

Also, what do people make of the ACES workflow, and is it worth the hassle for the benefits, if indeed there are any?

[goran]

Yes me too, best way.

I've not used all these LUTs but if the h264 to whatever LUT looks right to you, like the bottom image then Rec709 for colour space and gamma would seem the choice, that's what your h264 is using Rec709 primaries & Rec709 transfer curve.

To me using BMD colour space and gamma for ML raw -> final output in Resolve is pointless, no point using a logish transform for raw because you have full control over shadows, highlights, lift, contrast all within the raw tab.

Every intermediate this 3D LUT to log to that 3D LUT when working with raw to me is ***kery. Introducing interpolated error. If you start with flat or log source out of the camera then fair enough work log but with raw what is the point?

Try Rec709 colour space and gamma in your raw tab, apply your M31 whatever look LUT to your Output and tweak your raw settings mentioned above which will affect the raw data under your M31 LUT until you like what you see. Closer to your h264 -> M31 workflow previously.

The point is to get faster, closer to the look you're after and that's what LUTs are ultimately for. They're a fast way to get 70-80% of they way for most people. Also for creating dailies there's no substitute for LUTs.

Goran

[dyfid]

I'm coming round to dyfid's way of thinking on this.  My initial concern was the apparent limitations of the Rec709 colour space

Apparent limitations is a good description, but as you infer it's unfounded for raw.

Rec709 gamut is not an issue, it's generally the gamut the majority will view the final video in, a sRGB monitor of questionable ability, a Rec709 LCD or LED TV or even Rec709 home cinema projector.

Rec709 gamma curve would be a limiting factor if encoded into a lossy compression such as the h264 profile Canon's use at 8bit.

But in the case of raw, there is, even in Resolve 11 far more flexibility to revisit the raw data previewing through the Rec709 gamma transform, which is where the final video is heading anyway, whether it's transformed in a controlled way via an output LUT or just injected with contrast & saturation to suit.

It's totally different to dealing with Rec709 h264, as we all know, where you can't keep going back and revisiting the raw data adjusting highlights, shadows, lift, gain, white balance etc because the camera's done it for us. All that is done prior to transforming to Rec709 colour space and whatever gamma is chosen.

The Rec709 raw transform in Resolve is 16bit not 8bit, so thats 65536 levels to play within at 32bit precision and it's considered that even with a typical 2.2 - 2.4 gamma encoding on 16bit data, that 16 f-stops of DR can be comfortably distributed albeit not linearly. Choose linear for gamma with Rec709 in Resolve and it's even more comfortable but not good to grade in linear.

Absolutely no point imho to use log unless going to an intermediate for edit and grade outside of Resolve. That's what log is for, to efficiently maximise data in minimal bit depth. 8 & 10bit being most common. But again not raw data.

Where does log play a part in a typical raw development application like Lightroom, UFRaw, Rawtherapee, Darktable. No where to be seen because it's pointless.

In fact I'd suggest the future for raw development in Resolve, maybe next release is to increase the L*a*b toolset. In 11 BM introduced L*a*b colour space for the first time, that's a pointer to where they're heading. You can only do so much with typical RGB tools, 1D LUT's (lift gamma gain & curves).

and like most I'm reluctant to compromise any image quality therefore the expanded gamut BMD Film appeared to be a better choice, without necessarily knowing exactly what any of that in fact means.

However, considering the initial access to RAW data and 32bit floating point (so no clipping) then perhaps that's unnecessary?

Expanding the gamut via BMD Film is one thing but applying it to a camera with differing sensor capability is another. It gives a look, but whether it's detrimental or not. To me BMD is been promoted by the LUT creators to provide a flat log appearance as a starting point for their heavy LUT's in order to maximise the instant gratification and minimise the 'it all looks too contrasty and saturated'. Rather than work with primary grading on the raw to get it where you want and then apply the look LUT last.

raw process as I understand it is raw -> WB -> demosaic -> adjust exposure etc -> scale into output bit depth -> intermediate colour space XYZ -> Transform to output colour space (Rec709) -> Apply gamma curve or linear -> output

Every time we adjust WB the raw is demosaic'd again and the cycle continues.

3D LUTS are destructive so surely they should be avoided unless entirely necessary?  I know Peter Doyle refuses to use them so that's worth considering.

There's someone to aspire to for anyone who describes LUT ***kery as 'Grading'. A guy who uses L*a*b, custom tools and has a real passion for the art.

I'd love a definitive explanation on all this as I have a project coming up and I've yet to decide my final workflow approach.

The definitive explanation has got to be test and a 3D LUT is nothing magical its input value mapped to output value with a heap of interpolation in between based on a specific profile of a camera created under set shooting conditions, not a one size fits all.

I'd really like to know the best and cleanest way to emulate film stocks.

Mmm, mentions Peter Doyle and the goal is to emulate film stocks. Not something he'd do. Why emulate film stocks, the goal surely is to create imagery that provokes a feeling, a memory. From what I've heard and read he draws inspiration from everywhere other than a freaking film stock. Joking.

Also, what do people make of the ACES workflow, and is it worth the hassle for the benefits, if indeed there are any?

Nope, not for ML Canon raw.

[dyfid]

The point is to get faster, closer to the look you're after and that's what LUTs are ultimately for.

"The look you're after ", hmm. Look LUT's are for one of two things, instant gratification with least amount of effort or for the technicalities of onset, dailies and all that world.

I think grading is about crafting an image that evokes emotion and feeling not applying a look from a catalogue of looks.

They're a fast way to get 70-80% of they way for most people.

Look LUT's -> Instant gratification

Also for creating dailies there's no substitute for LUTs.

Technicalities of production.

All in jest, we do what we want and what we like, nothing else.

[baldavenger]

Thank you dyfid for that extensive and extremely informative response.  I learned more useful information in that entry pertaining to my most pressing requirements than I have in the last month of online research.  On many things you have put my mind at rest, and I have to believe that most people on this forum would find your clarifications invaluable.

On the subject of ACES, why exactly do you believe it is of no use to ML Canon raw?

[budafilms]

in my experience its better to use the bmd4k profile.

however, the bmdfilm to visioncolor lut is not meant to be used with canon raw material, but blackmagic cameras.. so perhaps you could try to kick it out of your workflow.. ?
does it look better than..?
can you post some screens with only the bmd film profile applied and with all the luts applied..

greet.s

Hi, I'm interesting in you recommendation: why you suggest BMD 4K instead of the other one?
I tried and I get a little bit of contrast.

Thanks

[dyfid]

Thank you dyfid for that extensive and extremely informative response.  I learned more useful information in that entry pertaining to my most pressing requirements than I have in the last month of online research.  On many things you have put my mind at rest, and I have to believe that most people on this forum would find your clarifications invaluable.

Only my opinion on what I've concluded myself nothing more, its upto individuals to make their own choices and conclusions through testing.

I'd actually preferred to be challenged and corrections made to be honest.

On the subject of ACES, why exactly do you believe it is of no use to ML Canon raw?

You'd require proper IDTs for each camera you wished to use and that really requires camera manufacturer input. Without that ACES for ML raw is flawed. Also do the cameras limited cababilities in gamut and DR make it worthwhile from a possible benefit point of view over non ACES workflow. Only benefit might be if dropping ML raw into a ACES workflow using more capable and suitable cameras with manufacturers IDTs, even then again its not a one size fits all.