Investigating RT-based processing workflow for EOS R5C footage (+ playraw request)

Long-time lurker.

TL;DR: if you have experience with (or knowledge about) processing R5C’s raw footage using RawTherapee, and/or a few seconds of raw footage from an R5C, please share…

Background:

I have been using RT to process Sigma fp’s CinemaDNG footage for as long as I had the camera. Now that the camera’s gone (not by my own volition), I am eyeing a potential change.

EOS R5 C seems nice in that it allegedly captures a wider dynamic range (14 EV vs. fp’s 12 EV), but not so nice in that allegedly best it can do is a proprietary and lossy raw format that Canon calls C-RAW.

On one hand, I’ve been running into dynamic range issues in scenes like urban night with a lot of existing light sources with the fp. On the other hand, my processing toolchain is open-source and I want to keep it that way.

I am looking to confirm things like:

  • Does RT support R5C’s C-RAW well across processing modules
  • Can C-RAW be converted into CinemaDNG with OSS, and how well
  • How good/bad is C-RAW compared to fp’s CinemaDNG

If no one has definitive evidence to answer that, I could find it out myself if I had a bit of footage to play with. Any footage would do. If someone has extra time, the perfect footage would be:

  • Highest quality, other than resolution (4K is OK) and FPS
  • Demonstrating possible rolling shutter
  • Perhaps a colour card in the frame and known light temperature

I just tested a CRAW CR3 from a EOS R6 and it seems to process normally. Here’s a sample CRAW from raw.pixls.us with everything turned on in RT.


Canon - EOS R6 - 3_2.jpg.out.pp3 (15.2 KB)

Link to Original CRAW.

@HIRAM Much appreciated! I can confirm that it works on my RT build, too. However, just to check, is this a frame from video footage, or a standalone still photo?

  • I suspect still raws may have different encoding than moving footage raws, because raw video footage is basically 30–120 stills per second, and in case of R5 C it’s 8K, its firmware needs to be very aggressive in compressing them, and as a result RT may not be able to read that.
    • Googling this a bit more, I seem to confirm that CR3 is not C-RAW, and unfortunately raw video can only be recorded in C-RAW. It looks like I’m looking for a .CRM file, not .CR3.
  • I heard that C-RAW is different from model to model, i.e. R5 C may output different raw data compared to R6. (This is in contrast to DNG, which is more or less consistent between models and brands.)

I am looking at the camera primarily from video footage angle as opposed to still photography.

CRAW is a still photo format. You must be thinking of the CRM which is completely different and a video format…

Yep, this topic is about raw video footage. As I mentioned, I have been processing raw video footage with RawTherapee previously, and I seek to continue doing so if I ever get a new camera.

Ok in your original post you seem to be talking about specifically 14-bit CRAW- those are only available with mechanical shutter stills. The video is not CRAW, it is Cinema Raw Light 12-bit. RT knows nothing about video.

It looks like there are the following formats:

  • .CR3: Canon raw.
  • .CRM: Canon cinema raw. I suspect it’s basically a container for a sequence compressed Canon raws, similar to CinemaDNG.

I’ll avoid using “C-RAW” in future, because it’s unclear what it even means at this point. I thought it means Cinema raw, but Canon’s sites seem down for me and I can’t look it up. The terminology is very confusing.

What I’m looking for processing can be described as: “whatever least-lossy raw video footage format EOS R5C can muster”. If it’s a single-file .CRM, I’ll extract it into stills, of course, before loading into RT.

The best you can get on R5c is:
8K:
12-bit Cinema RAW Light LT
8192 x 4320 / 50P / 2140 Mbps: approx. 31 Mins

Recording time based on 512GB card

6K:
12-bit Cinema RAW Light HQ:
5952 x 3140 / 25P / 1770 Mbps: approx. 38 Mins

Thank you. From my pre-research I am aware that it’ll be a 12-bit raw. This is equivalent to fp’s 12-bit CinemaDNG, except CDNG is fully lossless.

Naturally, it brings into question whether 14 EV stops is going to make a difference, if the output is at best 12 bit anyway—if anyone has an informed opinion on that, that’d be appreciated.

The question from my post still stands, if someone happens to have an R5 C :slight_smile: