Export Issues with c-log 3 footage

[Mr.MediaArts]

I am a high school Media Arts teacher and my program recently purchased the Canon R8. In the Lumetri Color settings tab under Source Clip we have checked the Override Media Color Space with the "Canon Log3/Cinema Gamut" option.

 

Everything looks great in Premiere, but when we export we are getting a desaturated look that does not match what we are seeing in Premiere. I've posted two screen grabs below, the one on the top is what we are seeing in Premiere, the one on the bottom is the export.

I've tried every export setting I can think of and this keeps happening. I've tried changing the viewer gamma to Quicktime 1.96, I've tried the quicktime gamma compensation lut...I've tried at least 15 different exports and the only thing that produces exactly what I am seeing in Premiere is a Quicktime with no video codec-rgb 8 bit...but the file size is insane, like 10gb for 15 seconds.

I've been scouring the forumns and youtube and I can find plenty of discussion of color space, but no solutions that have actually worked in which the export looks the same as it does in Premiere. There has got to be a way to achieve the same look we're seeing in Premiere with export settings that produce a managable file size...I'm sure it's probably relatively simple, but I can't seem to find all the right settings...PLEASE HELP!

[R Neil Haugen · Accepted solution]

First, please turn Display Color Management on. Unless you are an experienced color management person, in certain known workflows, or working on a system with all monitors calibrated and profiled by a competent tech, that should be on. Period.

Next, for most Mac users, Extended Dynamic Range switch also on.

Again for nearly all users, set auto detect log and auto tonemap to on. This will handle nearly all log and HDR forms of media correctly.

Display gamma ... Mac users ... what a mess Apple created for Rec.709 video but ah well, pick your poison. 

QuickTime/gamma 1.96  will come closer to displaying the same image outside of Premiere ... but only!!!! ... on Macs with Retina monitors without the newer "Reference" modes. The HDTV setting on those monitors with Reference modes,  correctly handles the display transform of Rec.709 with a monitor gamma of 2.4.

Web/gamma 2.2 is sorta a middle ground. Although in testing I read about, just done recently, it was demonstrated that most monitor set for web/gamma 2.2 diplayed still images at 2.2, but ...  they displayed Rec.709 video at gamma 2.4.

Broadcast/gamma 2.4 is the 'normal' setting for Rec.709 media, and is used by nearly all pro colorists for all Rec.709/SDR outputs. Note, they are mostly based on Macs, right? But no professionally produced and distributed media ... none ...is produced at gamma 1.96.

[Mr.MediaArts]

Thank you for your help! Turning on Display Color Managment seems to be the key in this case. Working on a 2017 iMac Pro with a Retina display, the Extended Dynamic Range, auto detect log and auto tonemap didn't have any affect on this particular clip, but it's good to know to just have those turned on for safety's sake. At this point I have been able to export a 4k video using the H.264 preset and I've gotten a match to what is displayed in Premiere. Big relief. 

[Spirited_Essence5CDD]

Exporting issues with C-Log 3 footage can stem from several factors, primarily related to color grading, LUTs, and file settings. C-Log 3 footage is designed to preserve dynamic range and requires proper color grading to bring out its full potential. If not correctly managed, it may appear flat or dull. Issues also arise if the export settings don't match the working color space or bit depth, which can lead to artifacts or color shifts. Using the right LUTs or a calibrated color profile ensures the footage looks accurate across different devices and editing software. Checking export settings can help mitigate these problems.

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