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Anyone have a workflow recommendation for Cinema Gamut to Rec709?

Anyone have a workflow suggestion for Canon C300 MKIII shot in Cinema Gamut (not raw)when applying a Canon LUT? Working in a Rec709 timeline. "Custom Lut" has an option for "input" and "output" as well, I assume you just leave both as Rec709 since the out has converted already? There seems to be little information on workflow specifics out there, hope someone can help shed some light in the topic.

Posted on Nov 15, 2023 2:53 PM

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Posted on Nov 16, 2023 7:02 AM

Hi, Not sure if will help you but my workflow for Canon C300 MKII is after import I select all the files and go to inspector, choose Extended from bottom, this shows you the Camera LUT applied, which is Apple's one, I then select Canon's own free LUT, in my case, CinemaGamut_CanonLog3-to-BT709_WideDR_65_FF_Ver.2.0.cube, which is far more accurate than the one Apple is using. You do NOT need to use 'Custom Lut', this is really when you are adding a type of style. Beauty of this way is no rendering is needed, well on my base M2 Mac mini anyway. I also do NOT transcode to ProRes, I leave in original XF-AVC Intra 422/10 400Mbps, the Mac can stutter occasionally because of this but its forcing FCP to go back to original before rendering or exporting. As a note I find that transcoding to ProRes does increase the contrast, not sure why but it should not. Regards, Charles

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Nov 16, 2023 7:02 AM in response to ChristineLord

Hi, Not sure if will help you but my workflow for Canon C300 MKII is after import I select all the files and go to inspector, choose Extended from bottom, this shows you the Camera LUT applied, which is Apple's one, I then select Canon's own free LUT, in my case, CinemaGamut_CanonLog3-to-BT709_WideDR_65_FF_Ver.2.0.cube, which is far more accurate than the one Apple is using. You do NOT need to use 'Custom Lut', this is really when you are adding a type of style. Beauty of this way is no rendering is needed, well on my base M2 Mac mini anyway. I also do NOT transcode to ProRes, I leave in original XF-AVC Intra 422/10 400Mbps, the Mac can stutter occasionally because of this but its forcing FCP to go back to original before rendering or exporting. As a note I find that transcoding to ProRes does increase the contrast, not sure why but it should not. Regards, Charles

Nov 21, 2023 5:32 AM in response to Tom Wolsky

Hi Tom,


I think I'm slowly getting to the bottom of it, I'm sure it has to do with the colour processing settings.


The thing with Canon's Cinema Gamut is its a very wide Gamut, I think FCP, if set to Standard Gamut SDR, is that its clipping both the top and bottom ends, highlight and shadow, of the LOG data. If I remember correctly Cinema Gamut exposed above and below 0-100 IRE, think it's 105 IRE? If this is the case the FCP is automatically clipping the LOG data when it's imported, unless told not to. Thing is the Wide Gamut setting in FCP is for 2020, not 709. May be I'll have to ask Larry Jordan about it.


Regards, Charles


Dec 14, 2023 9:10 PM in response to charlesteton


I know you've already more or less solved your issue...


...or...


No LUTs. No Color Board. Not processed in Compressor or any other app. These were processed and exported directly from an FCP storyline... basically in less than a minute (each).


The original was your sample: "LUT footage in Compressor nothing applied".


Only two (small) effects designed to be added to any clip applied.


These effects work with **every** type of footage regardless of camera manufacturer...


Whataya think?




Nov 20, 2023 1:08 PM in response to charlesteton

Hi Tom, Here are two exports to illustrate. One is pre import and other is what FCP does to it and on export. I've triple checked there is no LUT or colour space applied apart from 709, which original had and was graded under. You can see contrast has been bumped up, look in blacks and details of leaves have disappeared. Don't understand what ProRes is doing to it. Regards, Charles

Nov 21, 2023 4:36 AM in response to charlesteton

I have some MII and MIII media, but I can't download that LUT from Canon for some reason.


https://en.canon-me.com/supportproduct/tabcontent/?type=download&detailId=tcm:60-1167431&os=all&language=&productTcmUri=tcm:60-1126871


The download button on this page does nothing. Perhaps you could share it somewhere. Dropbox or WeTransfer. The link on the forum may not appear but it will be seen in notification emails.

Nov 21, 2023 5:50 AM in response to charlesteton

That is very strange. If I take screenshots of the original and the optimized ProRes, neither of which has the LUT applied, I see a difference in the media as you do. If I take a screenshot of the original with the LUT in FCP, and then optimize it, and take a screenshot of what should be the optimized file in FCP, the two are identical. If I export the original file with the LUT from FCP in ProRes and bring it back into the application, it looks identical to the original with the LUT.

Dec 14, 2023 12:08 PM in response to Tom Wolsky

Hi Tom,


Finally had time to get back on this problem.


I’m using compressor, latest version and latest version of Mac OS: 14.1.2 and 4.7, with latest version of Apple’s Pro Video update. In FCP the system works fine, as far as I can see, but Compressor is still not reading the Canon XF-AVC Intra 422/10 400Mbps correctly! I’ve searched the forums and I think it’s been an issue for a while from what I see and not necc to do with Canon C300 MK II but also MK III.


The issue I think is that Compressor does not understand that the LOG3 file with Cinema Canon CLOG3, Color Matrix: Neutral, Color Space: Cinema Gamut, is captured in a  color space that is well beyond 709 and even 2020, as graphs show above, and also that the Gamma is not standard.


I’ve managed to force it to behave correctly by applying an approx Gamma Correct of 1.12. The built in Canon LOG covertion files are useless, like being on magic mushrooms, if you apply Canon’s own correct LUT, in my case ‘CinemaGamut_CanonLog3-to-BT709_WideDR_65_FF_Ver.2.0.cube’ the all is good.


Please can we try and get the software developer to try and sort this out? I know Canon is so tight on profit margins that they could not be arsed to pay Apple for the ProRes license, to make life simple.  Would have paid a hundred or so extra, for the ProRes license to be sure.


Regards, Charles.


PS I'm trying to get Compressor to convert Canon XF-AVC Intra 422/10 400Mbps, CLOG3, Color Matrix: Neutral, Color Space: Cinema Gamut to ProRes 422 HQ in LOG, no color conversion or gamma correction necc.


Photos to follow.

Anyone have a workflow recommendation for Cinema Gamut to Rec709?

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