Need advice: Red & Sony color matching

[Bruce Schultz]

I could use some expert advice about getting Red 5K Dragon footage to match 4K Sony log footage shot on a documentary project.

I am having troubles getting the colors - especially red colors to match and I know this is a common problem, but what I need advice on is a workflow that would incorporate the very best elements of IPP2 and/or ACES in order to get the two cameras to color match. For instance, can you work with both cameras on the same timeline or do you need to separate them, process them separately and then recombine them with a saved look?

I am familiar with the IPP2 workflow and have found that it does a great job standardizing Red colors. ACES seems to be the necessary process for color standardization between the Red & Sony, however I have not yet explored the workflow to get this working. I'm just discussing colors at this point, tone/contrast adjustments are a more straightforward process of course.

If anyone can direct me to a tutorial or just explain a simple version of the Resolve/ACES workflow for these two different cameras, I would be most appreciative.

 

[Marc Wielage]

I think this can be done just through color correction, not necessarily through LUTs or color space manipulation.

What can help when shooting with different cameras is to have the cameras shoot color charts on the set (particularly the DSC charts, which are pretty good), which will tell you where and how the cameras' specific colorimetry are different from each other. Reds can be matched to a point with curves or keys, but there are cases where all you can do is make them close, not a 100% match. If it were that easy, you could have an iPhone match an Alexa, which clearly won't work in the real world.

Once you've found a general ballpark "starting point" that works for each camera, I'd use that as the beginning correction (first node or two) and then fine-tune it after that. It can be done -- it just takes time and experience. It's often just as hard to match two identical cameras when one of them is misadjusted in terms of color temperature or exposure; sometimes, the only recourse is to degrade the first camera rather than try to improve the bad camera.

 

[Dermot Shane]

If anyone can direct me to a tutorial or just explain a simple version of the Resolve/ACES workflow for these two different cameras, I would be most appreciative.

ACES has some advantages to get you to a starting point faster, there's a tutorial fromBaselight that is wortha look, maybe drop in at the 18 min mark if mathcing cameras is your focus, and you already have the basic's of scene refered workflow in your brain, otherwise i'd go from the start... and watch part two as well

most of the information translates to Resolve, with a few notable exceptions...

it also applies to PreLight, and that is the same price as Ressolve.. free....

imight it be worth looking at a workflow that uses CDL's from PreLight as a base for editorial even if you are finishing in Resolve?

 

[Bruce Schultz]

I fished around for some ACES tutorials and found enough information to start a Resolve project to see what could be accomplished. I was quite amazed at how well ACESsst worked to normalize and conform the colors between the cameras - Red Dragon 5K & Sony A7s 4K ProResHQ. I'll try to post a few before/after pictures later, but for now I think I've turned the corner on making ACES work for what it's mostly designed for - color matching (as close as possible) between different camera manufacturers models.

What I was experiencing at the outset was a distinct color shift on the color red in the footage between the two sources. This project featured a school where the uniforms included bright red T-shirts which were the main problem in the color matching issue between the two cameras. Once I put both cameras into their respective IDT's and set them both to Log, they very nearly matched the red color immediately. This as I understand it is exactly how ACES is supposed to work. The real trick though is to NOT set the IDT in the Settings page unless all footage is from the same camera(s), but I did set the ODT to Rec 709 since I'm monitoring on a 709 device. Once in the bin, it's easy to see which clips are from which camera and there you can block set the IDT for each camera - in this case RedLogFilm and Slog 3.

I always shoot charts on set and grey cards too, but they never show up in a Resolve edit XML/ALE input file do they? I've also found that the IPP2 LUT applied to RedWideGamutRGB/LogG310 really makes Red footage display the best colors yet. I haven't seen RWG_RGB/LogG310 as an option in the Resolve IDT list yet though. I am using Resolve 12.5.5 Studio.

So for now, the producer is emitting an audible sigh of relief now that he can see that the red colors are able to be matched. ACES footage still needs some degree of tone/contrast adjustments but that is a very straightforward process in Resolve.

Thanks for your suggestions.

 

[M Most]

... for now I think I've turned the corner on making ACES work for what it's mostly designed for - color matching (as close as possible) between different camera manufacturers models.

That's only part of what it was designed for. The other (and potentially more important, at least to studios) parts are an archival intermediate colorspace that encompasses essentially the entire visible color spectrum, and the ability to re-target deliveries to all known and unknown delivery formats easily (or at least with minimal intervention).

The real trick though is to NOT set the IDT in the Settings page unless all footage is from the same camera(s), but I did set the ODT to Rec 709 since I'm monitoring on a 709 device. Once in the bin, it's easy to see which clips are from which camera and there you can block set the IDT for each camera - in this case RedLogFilm and Slog 3.

I always shoot charts on set and grey cards too, but they never show up in a Resolve edit XML/ALE input file do they? I've also found that the IPP2 LUT applied to RedWideGamutRGB/LogG310 really makes Red footage display the best colors yet. I haven't seen RWG_RGB/LogG310 as an option in the Resolve IDT list yet though.

If you're using ACES, Red RAW footage is debayered directly to linear light with AP0 primaries (AP1 if you're using ACEScc or ACEScct). The Red gamma settings are not used or applied. The Red wide gamut/Log3G10 processing only applies if you're using the "normal" processing path. Not ACES. You need to choose one or the other (and needless to say, they cannot be mixed because the processing path is a global setting in Resolve). The RedlogFilm setting (and all other specific Red IDT's) is supplied for RGB footage that was shot on Red and debayered using those settings. Not for Red RAW files.

BTW, the inability to mix ACES and non-ACES processing in Resolve is one of the things that frustrates many of us who have used Baselight (where you can do that rather easily). I understand why they implemented it that way (see my earlier comment about deliverable re-targeting......) but it is still frustrating at times.

 

[Bruce Schultz]

Mike, guess I should have used the words "in part" instead of "mostly" . . designed for. I think the archival intermediate function and re-targeting of delivery formats are great tools, but I doubt I'll be using those features any time soon as an owner/operator and part time color masseur. Those functions are way past my pay grade at this point.

Thanks for your cogent comments .

 

[Bing Bailey]

http://nofilmschool.com/2017/04/never-color-match-again-filmconverts-cinematch

 

[Bruce Schultz]

http://nofilmschool.com/2017/04/never-color-match-again-filmconverts-cinematch

I'll bear that in mind for projects next year after it's released in November.