Photo and Video Editing

Don’t Use C-Log 3 / Cinema Gamut on the Atomos Ninja V

Earlier this year I posted a video to my YouTube channel demonstrating how to setup the Atomos Ninja V monitor to record video externally from the Canon EOS R5 and R6. In that video, I mentioned that 4K video recorded externally on the Ninja V appears virtually identical to 4K video recorded internally on either the EOS R5 and R6.

And for the most part, that remains true, as evidenced by the following comparison shot using C-Log BT.709. 4K internal video on the left, 4K external video on the right.

C-Log 3 BT.709 Internal on the EOS R5 (Left) / C-Log 3 BT.709 External on the Atomos Ninja V (Right)

But since I made that video, Canon updated the firmware of the R5/R6 to include support for C-Log 3 and the Cinema Gamut color space. Great news for both cameras, but the Ninja V does not render Cinema Gamut correctly.

For example, take a look at the following comparison. C-Log 3 Cinema Gamut recorded internally on the left, C-Log 3 Cinema Gamut recorded externally to the Ninja V on the right.

C-Log 3 Cinema Gamut Internal on the EOS R5 (Left) / C-Log 3 Cinema Gamut External on the Atomos Ninja V (Right)

The colors in the Ninja V footage appear oversaturated, and there is a noticeable skew towards yellow. You can especially see the saturation push in the magenta, purple and green color chips, and the amount of yellow that has been pushed into the color of the table at far right.

I spoke with Atomos support about this in October, 2021 and they said this was a known limitation with the Ninja V. How long this has been a problem, or when/if it will be resolved, I’m not sure.

What I do know is that (for now) it’s best to avoid C-Log 3 Cinema Gamut when recording externally to the Atomos Ninja V. C-Log 3 BT.2020 and BT.709 are fine, as is C-Log BT.709 (as demonstrated earlier) on the Ninja V, but Cinema Gamut will cause a lot of headaches in post when color correcting footage.


Here is the “Complete Setup in 5 Minutes” video for the EOS R5/R6 and the Atomos Ninja V.


  • Charlie
    October 19, 2021 at 10:52 pm

    How ! Nice website here !
    I have also issu with Davinci Resolve about that. Trying to put a CST to go from Cinema Gamut/Clog3 to Cineon Film Log but the color way over kicked so i tried to change Cinema Gamut to Rec709 ….it works but i loose too much color data.

    I though my Atomos settings was wrong, like i didn’t put Cinema Gamut but yes i did, but if i read the exif of the Ninja files, i see Color matrix REC709, What the heck ? Maybe Prores is not ok with Cinema Gamut ?

    • John
      October 27, 2021 at 10:20 pm

      Same here, i sure had set my canon r6 to clog3 and rec 2020. Put the same settings on the record tab from the ninja v. I recorded everything in prores hq. Later in davinci resolve i did a cst to rec 709. The outcome was very saturated. I checked the files with Mediainfo. Mediainfo showed that the files were recorded in atmos.709 (rec709 i guess?). But the metadata in davinci said rec.2020. In the end i did a cst where i have set the input on rec709/clog3 and the output on rec709. That worked, but your complete workflow will be rec709. So it has to be a bug in the ninja v when recording clog/clog3 in prores. I hope they will fix this!

  • Mo
    November 5, 2021 at 6:01 pm

    Thanks for updating us on this, I exclusively use these modes so add it to the list of ever-growing issues the Atomos has with the R5 including that it did NOT solve the overheat issue. I emailed Atomos earlier this year and they responded almost a month later stating their team is getting an R5 to test out the issue, and haven’t heard back since. 😐

    • Greg
      December 11, 2021 at 10:48 am

      I use my R5 as a B-cam to my C70 for interviews and B-roll. I remove the cards and make sure the lcd and evf turn off quickly. I have run for at least a couple of hours without ever seeing an overheat warning when recording 4K HQ to the Ninja V. It’s unfortunate we can’t record internally at the same time if we want to keep from overheating, but at least there is a solution. Cards out, LCD/EVF off and you’re set for very long record times.

    • Nick
      January 4, 2022 at 12:05 pm

      Any news from Atomos regarding this issue.? I’m having the same problem matching C_Log 3 / Cinema Gamut recorded onto my NinjaV (from Canon R6) with my Canon C300 Mark iii Cinema Gamut. The ProRes / Cinema Gamut has shifted considerably on the Ninja.

  • Charlie
    November 23, 2021 at 11:07 am

    Hi there ! Any news from Atomos about this shift Cinema Gamut now ?
    Todd, what you think of using only CLOG with BT709 space on R5 with Atomos ? Struggling between 709 and 2020…my style is more less saturated than HDR for now so :/

    • Charlie
      November 24, 2021 at 8:20 am

      Well, i did a test with sunset, CLOG 3 Cinema Gamut is way better. BUT : The color shift (more magenta) is on the internal footage. Explaination : I recorded internally and externally with Ninja V : One with CLOG3/2020 an one with CLOG/CINEMA GAMUT. If i put this 4 footages on davinci, put a CST node i see that Atomos CLOG3/2020 and internal is exactly same. But with Cinema Gamut the trick is to put put REC2020 input on atomos footage and you get exactly same image as REC2020 footage.
      BUT the internal Cinema Gamut one have a shift in the magenta even if i put Cinema or REC2020 in the input CST. So…I compared REC2020 Atomos footage and the Cinema Gamut Atomos Footage : the color is same but with better transition.
      If i compare then Cinema Gamut internally with rec2020 internally the color is shifting magenta like if you choose Neutral or EOS gamut in CLOG 1…. Definitely my workaround is to choose CLOG3/Cinema Gamut on the canon, record externally with Atomos, then on davinci put a CST with input : rec2020,

    • Todd Dominey
      January 14, 2022 at 12:18 pm

      Hi Charlie – didn’t see your comment until now. I’m not aware of any changes, but one thing I’ve read since publishing this article is that the issue may be less Atomos and more what HDMI is capable of delivering. From what I gather, Cinema Gamut may simply be too big a color space to be carried over HDMI (and can only be recorded internally). So yes, still avoid using Cinema Gamut when recording externally.

      • Tom C
        February 3, 2022 at 4:15 am

        I have exactly the same issues matching R5 & C70 CLOG3 Cinema Gamut. Spend 8hours testing it all. However I don’t think it’s a Ninja V issue nor a HDMI cable issues. I mean, the C70 also uses a HDMI cable to carry the CLOG signal to the ninja just like the R5. The main difference is the HDMI port size on the cameras. Tested with 2 R5, 2 Ninja and a C70. Wether in 709 or C Gamut, it’s still the same problem. Could not get them to match. 😠

        Only saving grace is I can still match them in post. But I hope to solve this problem at its root. More trouble shooting to come.

        Honestly I think it’s the R5 issues. When I setup Resolve Colour management for CLOG3 C Gamut, the C70 footage coming off the ninja looks great and the R5 has the same issues as you mentioned in your Post.

        • Charlie
          February 17, 2022 at 6:40 am

          Any update this year ?

  • John M
    March 11, 2022 at 9:04 pm

    Does this also happen on the Atamos v+? Or even an issue on the V as of late?

    • Todd Dominey
      March 22, 2022 at 7:02 pm

      I don’t own a V+ to confirm 100%, but from what I understand the V+ is exactly the same as the V, but with added support for 8K and 4K 120 (using other cameras besides Canon).


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