RGB-transfer of scanned film print to scanned film negative

Hello DaVinci Resolve experts,

Since my research within DaVinci Resolve (Manual) and in the internet didn't lead to a trace I hope for feedback in this forum.

We are working with film footage scanned with the Cintel Scanner 2:

1. the original film negative
2. a film print (positive copy of the film negative)

The scanned footage of both media is imported in a DaVinci project. Both tracks are synced in the timeline.

This is clear that the scanned film negative appears as a positive by using the according LUT - but with the typical flat profile that now needs to be graded, scene by scene.

The film print is result of the analogue 'color grading' process, scene by scene, in the film laboratory, authorized by the author and the cinematographer. That's why the film print, respectively the scan of the film print, can bee seen and used as a 'master' - concerning the look of luminance and colors.

Now a manual scene by scene color grading of the scanned film negative would be necessary - always switching to the scanned film print as the reference.

It is obvious that DaVinci Resolve recognizes the look of the film print because the scopes give precise information on the R-G-B values.

When the manual color grading of the scanned film negative is readily done in result the scopes of both, film print and film negative, look (almost) the same.

My question is:

Is there a workaround in DaVinci Resolve that allows to transfer the R-G-B values of the film print (as analyzed by DaVinci) to the color grading of the according film negative - in result leading to the identical look in terms of R-G-B?

My idea is that this transfer would produce a perfect result if it is done automatically.

A hint of you experienced users would be great.


Thanks a lot,

Herbert

Taking a step back, if you have a finished film print, why redo the work on a negative?

Thanks for aksing. The quality of the negative is much better: resolution, grain and not injured by use.

You could try the Shot Match feature, which is probably the closest to what you're asking. Page 2150 in the Resolve 16.1 manual.

SHOT MATCH is a very good hint, and I will dig a little deeper now. I had done some research on this feature but understood that it adapts a (manually) graded color correction to shots of a similar light situation. Now I found an interesting experience report on SHOT MATCH in the forum (https://forum.blackmagicdesign.com/viewtopic.php?t=56149), and I will follow up on this. Then I will write some lines here on the output.

=Is there a workaround in DaVinci Resolve that allows to transfer the R-G-B values of the film print (as analyzed by DaVinci) to the color grading of the according film negative - in result leading to the identical look in terms of R-G-B?

No, there is not. I've done about 30 film-based projects this year, and they were all done meticulously by hand. If there was a previous home video (or broadcast or streaming) release, I bring that into Resolve and eyeball it, then match it using scopes and stills.

The print may not represent the best that the film can be, and it may not necessarily show how it looks projected on a screen. Bear in mind that film projection is at 5400°K and video displays are traditionally at 6500°, plus film brightness is about 48 nits vs. 100 nits for Rec709 video. It's not an apples-to-apples comparison.

The print and negative may have also aged a bit, so the chemistry has drifted to the point where the color is unstable or at least not where it was when it was originally shot and processed. You have to use experience and good taste to try to color-correct the film negative scan in a reasonable place, and still try to respect the work of the cinematographer and the intentions of the filmmakers.

But there is no fast way and there's no easy way -- just hard work, lots of time, and knowing some shortcuts to make the process go faster without sacrificing picture quality. (I'm on record as not being a Shot Match fan, but I think it can help in dailies or with unskilled people when they have to get through something quick and easy.)

one more thought, like Marc and many other's here, i have some seat time with film

- the only place the DP+Director's vision is accuratly repressented is the orignal lab answer print
release prints are at the minimum two generations (IP +IN) removed from the answer print, and therefore have more contrast for sure, and whatever the lab's tolerance values were on the day(s) your release print was struck added to the mix... end game is a release print can be a fair bit off the answer print and still be inside lab tolerance values, and may not represent the vision of the creative with any accuracy

the only place the DP+Director's vision is accurately represented is the original lab answer print... release prints are at the minimum two generations (IP +IN) removed from the answer print, and therefore have more contrast for sure, and whatever the lab's tolerance values were on the day(s) your release print was struck added to the mix... end game is a release print can be a fair bit off the answer print and still be inside lab tolerance values, and may not represent the vision of the creative with any accuracy

We have gotten Premiere Vision prints struck off the camera negative, and of course in the D.I. film days, quite a few movies were created with digital negatives, so technically they avoided the IP/IN stage.

One other caveat is that the print the director approved in the 1970s, 1980s, and 1990s has faded in the last 20 years. And there's no easy way to project film and match it to a video monitor. We actually did it for Disney back in the day with a portable Arri Loc-Pro film projector, but it was a huge pain in the ass, and you still had the problem of color temp and brightness.

Memories and references are illusory. I've had plenty of remastering sessions for studios where they invited me over to watch their library print, and five minutes in we shook our heads and said, "welp, it's all faded to magenta," and they'd just say, "hey, do your best and don't screw it up!" And there are also cases where the director's memory or intentions have faded after 20-30-40 years, and they come in and see the film on a monitor and say, "you know, I want to go in a different direction than the way it was released." We had that happen with Robert Wise on Sound of Music, where he wanted the film very cold (that is, minus-red) and looking a lot more dreary than he did back in 1965. That was a deliberate creative choice... but the fans went crazy when they saw the home video release. Years after Wise passed away, Fox quietly went back and redid the transfer and made it bright and warm and colorful, which is how most people think of the film.