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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 BT.709 Neutral Color Matrix / 4K Internal EOS R5 (Left), 4K External 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 / 4K Internal EOS R5 (Left), 4K External 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.

Video

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

5 Comments

  • 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 ?

    Reply
    • 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!

      Reply
  • 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. 😐

    Reply
  • 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 :/

    Reply
    • 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,

      Reply

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