Kodak Vision3 in DaVinci Resolve - use ACES or don't bother (film colour management question)

[Stephen Perera]

Interested to hear about colour management 'tips' importing Kodak Vision3 footage into DaVinci Resolve and using, or not, ACES or DaVinci default colour management

Thank you

[Dirk DeJonghe]

Here is a document that I send to customers, this question is asked frequently. Please share freely.

Some people try to tweak Cineon Log with contrast settings, this is wrong.

 

 

CineonLog_DaVinci.pdf

[Robin Phillips]

You usually want to set your input profile for film as cineon, but its not necessarily going to be perfect due to a variety of reasons (say you are mixing 2 week old film with 6 month old film, there will be subtle differences). I've also worked with some labs who had instructed me to use arri log c instead of cineon, so you want to talk to your lab/scan house just to be sure. 

As for Aces vs Resolve color management, I think it just depends on your needs, what you're mixing, how heavy a vfx show it is etc. Personally I lean toward ACES when dealing with heavy vfx where Nuke is the main compositing tool due to the linear workspace, but Im not convinced thats vital. It seems to make things easier for the VFX houses and simpler to solve color management problems though should shots come back wonky. 

[Phil Rhodes]

I don't think I'm particularly daft about this stuff, but I've spent quite some time staring at the colour management settings in Resolve and concluded that what the world needs is a large, poster-sized wall chart showing the exact path the image takes through the application, indicating where each process is performed and which controls affect them.

In my view it is not well organised. For instance, some settings are labelled as colourspace controls, but deal also (or optionally, or sometimes) with luminance handling too. It mixes concepts, it's extremely poorly documented, and it gives every impression of having been allowed to grow and evolve without much care or attention being paid to comprehensibility. Of course, mention changing it and a thousand colourists who have their own special sauce to make it work will immediately complain and deny any possibility of improvement, but that attitude leads us down the same path taken by things like Pro Tools, which have been added-to and expanded for decades in a manner that's created a chaotic beast which is highly familiar to long-term users but impenetrable to anyone else.

It's a slow rot that affects professional software and I don't think most of Resolve has these problems - it's fast and well done - but the way the colour management setup works is a nightmare from the seventh circle of Hades' own eternal damned kingdom.

[Jon O'Brien]

Still being new to colour grading, could someone explain to me how colour management in davinci resolve differs from just ordinary manual, garden variety colour grading of, say, scanned 16mm film?

Edited May 7, 2023 by Jon O'Brien

[Stephen Perera]

On 5/6/2023 at 12:20 PM, Dirk DeJonghe said:

Here is a document that I send to customers, this question is asked frequently. Please share freely.

Some people try to tweak Cineon Log with contrast settings, this is wrong.

 

 

CineonLog_DaVinci.pdfUnavailable

very kind of you to share this….much appreciated!

[Stephen Perera]

18 hours ago, Robin Phillips said:

You usually want to set your input profile for film as cineon, but its not necessarily going to be perfect due to a variety of reasons (say you are mixing 2 week old film with 6 month old film, there will be subtle differences). I've also worked with some labs who had instructed me to use arri log c instead of cineon, so you want to talk to your lab/scan house just to be sure. 

As for Aces vs Resolve color management, I think it just depends on your needs, what you're mixing, how heavy a vfx show it is etc. Personally I lean toward ACES when dealing with heavy vfx where Nuke is the main compositing tool due to the linear workspace, but Im not convinced thats vital. It seems to make things easier for the VFX houses and simpler to solve color management problems though should shots come back wonky. 

No VFX at all in my stuff it’s all one man band. I will stick to the default colour settings in DaVinci Resolve I think as ACES is a bridge too far for anything I will do that’s for sure and will probably frustrate me as much as ColorSync did back in the day when designing for print and dealing with colour photography scans on Apple Macs via Photoshop or whatever it was back in the 80s and 90s.

I wasn’t even aware you had to put in an input profile for film scans…..I always get .dpx files that magically appears intact as one video file after importing.

[Dirk DeJonghe]

It helps to understand how film densities of a negative are converted into Cineon Values.

Have a look at the sensitometric curve.

The Y-axis is the film density, increasing with exposure (X-axis).

The Cineon Log file is created by scanning (linearly) the density of the film and writing them in Cineon Values ranging from 0 to 1023 (for 10 bit). Why is it called LOG since it is a linear transpose of film densities?

Very simple, the X-axis is LOG Exposure, so the relationship of Exposure to Film Densities to Cineon Values is Log.

During scanning from negative, the scanner will calibrate itself to the base density of the unexposed film (orange mask) in order to shift the RGB curves  so that the black level falls at about 95CV. 

 

 

[Robin Phillips]

8 hours ago, Jon O'Brien said:

Still being new to colour grading, could someone explain to me how colour management in davinci resolve differs from just ordinary manual, garden variety colour grading of, say, scanned 16mm film?

among other things, it just makes life easier. You can take your film scans and tag them as cineon and set an output transform (say rec 709), and you're suddenly not wasting time with as much technical work as you are now able to just dive in creatively. It also means that you can bring in other cameras, say an arri alexa, set it up as log c and with the same output, and now your footage is more or less living in the same general world color wise. This color management also makes outputting to different color spaces a little easier since your material was effectively normalized on the input side. You should still manually check your color for each space instead of relying on a final output transform to magically get it right, but it does make life easier