Footage from Canon C70 has a gamma shift in Premiere (on PC only)

[PhilSchmulian]

Hi, 

Whenever I bring footage from the Canon E70 (.MXF files), there is a noticeable gamma shift in Premiere, but only on my PC. It looks fine on VLC and MPC, and also on Premiere on Mac (I've tested the same files on Mac, no issue).

The issue is ONLY in Premiere, and ONLY on PC (I haven't been able to test on another Windows PC, just my own). 

This is how it's supposed to look (and how it looks in VLC and Premiere Mac): 

And this is how it looks in my Premiere for Windows: 

And when I export said footage directly through Premiere, I still get this gamma shift, but if I use the same settings, but export through Media Encoder, it looks normal (aka without the gamma shift).

I've messed around with the settings and just can't figure it out! Help me please!

I'm running Premiere Pro 24.5 on Windows 11 and my GPU is GeForce RTX 3070 (my NVidia Studio driver is always updated).

[Ann Bens]

Please read these docs:

Tone mapping in Premiere Pro

Color management in Premiere Pro

[PhilSchmulian]

Thanks @Ann Bens, but that's not it. 

If I enable Auto Tone Mapping, it just automatically applies a Rec709 LUT to the footage (or at least that's what it looks like). I want it to still look LOG, but with the correct gamma, not this unusually high gamma. 

If I uncheck "Display Color Management" in the Lumetri settings (it's already checked by default), it just makes the gamma even higher! 

[Ann Bens]

@R Neil Haugen 

[R Neil Haugen]

First, lose the idea that everything is a LUT, ok? They actually use algorthms for most transforms now, vastly superior and capable math based processes.

Second, is that footage file set to full or video range? You can check in the free utility app MediaInfo ... drag/drop the file onto that utility's desktop icon, then go into "Tree View" and it will show in the data.

Probably drag/drop the image onto the test area of the reply box so we know exactly all the details of the clip.

Next ... with most media these days, due to the new color management available in Premiere, I would suggest ...

• Display color management ON
• auto detect log ON
• auto tonemapping ON
• sequence still set to Rec.709
• use ONLY presets without HLG or PQ in the preset name.

[Kevin-Monahan]

Hi @PhilSchmulian,

Can the team get more info? See, How do I write a bug report? @Sumeet Choudhury might be able to assist.

Thanks,
Kevin

[PhilSchmulian]

Hi @R Neil Haugen. It's been a while, but here's what you requested: 

General
Complete name : A047C165_240727SP_CANON.MXF
Format : MXF
Format version : 1.3
Format profile : OP-1a
Format settings : Closed / Complete
File size : 666 MiB
Duration : 37 s 920 ms
Overall bit rate : 147 Mb/s
Frame rate : 25.000 FPS
Encoded date : 2024-07-27 07:16:42.000
Writing application : CANON EOS C70 1.00

Video
ID : 2
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High 4:2:2@L5.2
Format settings : 2 Ref Frames
Format settings, CABAC : No
Format settings, Reference frames : 2 frames
Format settings, GOP : M=3, N=12
Format settings, wrapping mode : Frame
Codec ID : 0D01030102106001-0401020201316001
Duration : 37 s 920 ms
Bit rate : 143 Mb/s
Maximum bit rate : 150 Mb/s
Width : 4 096 pixels
Height : 2 160 pixels
Display aspect ratio : 1.896
Frame rate : 25.000 FPS
Color space : YUV
Chroma subsampling : 4:2:2
Bit depth : 10 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.645
Stream size : 645 MiB (97%)
Color range : Min: 0, Max: 1023, Chroma range: 1023
colour_range_Original : Full
Matrix coefficients : BT.709
Delay_SDTI : 36839520

Audio #1
ID : 3
Format : PCM
Format settings : Little
Format settings, wrapping mode : Frame (AES)
Codec ID : 0D01030102060300
Duration : 37 s 920 ms
Bit rate mode : Constant
Bit rate : 1 152 kb/s
Channel(s) : 1 channel
Sampling rate : 48.0 kHz
Frame rate : 25.000 FPS (1920 SPF)
Bit depth : 24 bits
Stream size : 5.21 MiB (1%)
Delay_SDTI : 36839520
Locked : Yes

Audio #2
ID : 4
Format : PCM
Format settings : Little
Format settings, wrapping mode : Frame (AES)
Codec ID : 0D01030102060300
Duration : 37 s 920 ms
Bit rate mode : Constant
Bit rate : 1 152 kb/s
Channel(s) : 1 channel
Sampling rate : 48.0 kHz
Frame rate : 25.000 FPS (1920 SPF)
Bit depth : 24 bits
Stream size : 5.21 MiB (1%)
Delay_SDTI : 36839520
Locked : Yes

Audio #3
ID : 5
Format : PCM
Format settings : Little
Format settings, wrapping mode : Frame (AES)
Codec ID : 0D01030102060300
Duration : 37 s 920 ms
Bit rate mode : Constant
Bit rate : 1 152 kb/s
Channel(s) : 1 channel
Sampling rate : 48.0 kHz
Frame rate : 25.000 FPS (1920 SPF)
Bit depth : 24 bits
Stream size : 5.21 MiB (1%)
Delay_SDTI : 36839520
Locked : Yes

Audio #4
ID : 6
Format : PCM
Format settings : Little
Format settings, wrapping mode : Frame (AES)
Codec ID : 0D01030102060300
Duration : 37 s 920 ms
Bit rate mode : Constant
Bit rate : 1 152 kb/s
Channel(s) : 1 channel
Sampling rate : 48.0 kHz
Frame rate : 25.000 FPS (1920 SPF)
Bit depth : 24 bits
Stream size : 5.21 MiB (1%)
Delay_SDTI : 36839520
Locked : Yes

Other #1
ID : 1-Material
Type : Time code
Format : MXF TC
Frame rate : 25.000 FPS
Time code of first frame : 10:13:59:13
Time code of last frame : 10:14:37:10
Time code settings : Material Package
Time code, stripped : Yes

Other #2
ID : 1-Source
Type : Time code
Format : MXF TC
Frame rate : 25.000 FPS
Time code of first frame : 10:13:59:13
Time code of last frame : 10:14:37:10
Time code settings : Source Package
Time code, stripped : Yes

Other #3
Type : Time code
Format : SMPTE TC
Muxing mode : SDTI
Frame rate : 25.000 FPS
Time code of first frame : 10:13:59:13

[R Neil Haugen]

Thanks!

cr)

And yea, one obvious problem, is it's full range but "only" YUV (technically Y/Cb-Cr) ... which should always be encoded as limited range. It does NOT change the amount or quality of data, just how it's written to file.

And the rules for Rec.709 media clearly have been for over a decade, that all YUV is 'limited', and the RGB 12 bit stuff is full range. That's what hardware expects, by the way.

So ... there's a Lumetri  preset, "limited to full" or "legal to data" something like that, that I would drag/drop on the clips in the bin, and see what that does. First step.

As if you see it wrong inside Premiere, and do any corrections ... it will be more wrong outside Premiere.

[R Neil Haugen]

Oh, and if you messed with the monitor legal/full settings, or those of the GPU controls, undo that. It should be set to something like 'auto levels' or limited for Rec.709 media. Period.

It will automatically correctly display it as full range then ... as it will also correctly display any RGB  12 bit you might come across also. Doubt you see much of that though ...

[PhilSchmulian]

Ok, many months later, here's what I have observed: 

• It's Canon C70, not E70. I don't know where I got E70 from, since that doesn't exist.
• I have since tried it on another PC, also running Windows 11, and the problem persists there also. 
• The problem has something to do with the MXF container of the video files. If I rename the files to .MTS, they appear normally on Premiere, as they're meant to. I have no idea why. My workaround has been renaming all the clips' extensions. 

I hope Adobe can figure out why Premiere on Windows shows MXF files (at least the ones created by Canon C70 cameras) with a gamma shift, and why renaming the extension to MTS fixes it.

[R Neil Haugen]

I would love to see the MediaInfo report for after the change to mts ... does that somehow change something in the file header? I don't know how it would ... but maybe?

And I'd love a chance to get a file to test myself. So if you could share something via dropbox type link, it would be ever so nice.

[jamieclarke]

Hi @PhilSchmulian - As Neil has said it would be good to get a sample file so that we can investigate.  If you want you can email a link to jamiec@adobe.com