Gamma Shift on iMac but not Macbook

I don't own a mac, but steve shaw from lightillusion just said try replacing the OS's icc with a rec. 709 color profile or null. even though it won't affect premiere, it might affect quicktime as supposedly its color profile aware. i think vlc runs separate of your OS's profile so you have to set it to openGL output.

The theory is, premiere is right and quicktime is wrong, not the other way around. If you import the footage directly into premiere in both systems, it should look the same unless the monitor is gamma 2.4 vs 2.2 in your monitor's actual power dim settings or something.

The problem with taking screenshots and comparing against premiere is that a quicktime or mac viewer software is color aware and premiere is not. The correct test would be export as png and import into the other system's premiere and verify against a RGB pixel sampler or scopes.

If you've read through this thread, it's been clear that there are several different color space/profiles on different Macs. Every different 'major' delineation seems to have a slightly different profile. The MacBook Pros are not using the same color profile as the full Mac desktops ... and in fact, separated by when they were made, there seem to be two or three different precise profiles between M-book Pro's alone. The desktop P3 monitors each have a slightly different profile depending on size of monitor. What a ... joy.

So there's no way to say "the same setup on this Mac product does, x, so this one should also."

None of the Mac products seem to be set for Rec709 broadcast standards ... except for a couple users found that magically the FCPx seemed to do so, when exported into a properly managed Rec709/sRGB system. Well, that's Apple being Apple, of course, always built to give the House apps an advantage within the OS that's not shared with "outside" vendors.

This would be easier to work with if the Adobe apps came with user-settable color management, rather than just being built to run on a system fully setup to run on sRGB/Rec709 "natively".

Neil

What's the profile (or color space) the OS and monitor are set to use on the Imac Pro? And of course, what gamma is it using? Those are the first things one needs to know. Sadly, Mac doesn't give a lot of user-settings on some of these sorts of things anymore, but ... we need to know how yours is set to start with.

Next, you do have to understand that QuickTime is never a valid choice for checking color/gamma. VLC/Potplayer are the two main generally available players that actually handle color of the files they display correctly within their own app.

And last ... Chrome & Safari don't properly handle or respect color management settings, so they can be all over the place. Firefox does.

I would prefer that PrPro gave some user settings for color managing as Resolve does. But until then, the main thing to know is PrPro works very tightly controlled in sRGB which is the basis of Rec709 professional video standards. And is built around a gamma of 2.4 or 2.2. Unless the codec standard for a particular flavor of a codec states otherwise, PrPro will both "see" and export files that are "full range" ... or "data levels", with the signal extending from 0-255 in 8-bit terms. Some apps expect to 'see' or play 16-235. And may play back files in the limited space, at which point, PrPro exports will look low-contrast, mushy, and low-saturation.

So when you have a file that in the PrPro program monitor looks good, and is full-range with saturation ... and looks low-contrast or low saturation outside of PrPro, there's an issue with the profile or gamma (or both) of the monitor or of the player. Or both.

We had a thread about this a couple years back, with someone insisting that as YouTube and QuickTime showed his exports flat & low saturation, it was a PrPro problem. He was rather shocked when he finally took a short export to a TV station, and got someone to put it up on their expensive, highly calibrated system ... and it looked just like it did in PrPro.

A PrPro export corrected on a system with appropriate color settings, viewed on a system with appropriate settings, will be within vary close bounds.

Now ... here's a question answer with the head of color for PrPro (slightly modified/condensed for clarity). Maybe some of it will be of use to you.

Neil

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Question: What space/profile should the "confidence" or program monitor be set to?

Best is to use a display setting and viewing environment that matches your main audience group’s viewing habits.

The Premiere content coming out the display port IS full-range (0-255) Rec.709. So ...

• For TV viewers in a dim environment, Rec.709 is the best fit for viewing Rec. 709.
• For computer viewers in an office environment, sRGB is the best fit for viewing Rec. 709.

sRGB was designed for good viewing of (unconverted) 709 content in an office environment.

The sRGB concept expects that the consumer end video player is not color converting from Rec. 709 to sRGB.

Such a conversion is likely to clip shadow details found in Rec. 709 video.

Question: Should the monitor controls or GPU controls be set to data levels (0-255) or video levels (16-235)?

Note that this question is actually unrelated to the first one.

Set the monitor for full range (0-255) as the content is full range.

Your Digital Color Meter and your Premiere eye dropper should read the same number values on Color Bars. Such as 102 for the grays.

Question: When working with a b-cast/tv monitor say via Decklink ... what are the proper protocols?

There are several ways to connect a second monitor, depending on type:

    1) Connected to the main display card or port.

    Part of the desktop.

    Can have desktop icons, OS menu bar and Dock.

    Can be mirrored in the OS Display control panel.

    Accessible to all apps.

    The rules for the first display applies to this display.

   2) Connected using Adobe’s Transmit and a 3rd party card and driver.

    Is not part of the desktop, cannot be mirrored in the OS, not accessible to most apps.

    Accessible to Ae and Pr only.

    The 3rd party driver receives the content in memory as full range, overranged, Rec. 709, and converts to the display format.

    The display can be a reference monitor, a TV set, HDR-capable etc.

    The display setup must be one supported by the 3rd party driver.

    This display interface is entirely controlled by the 3rd party card and driver.

    Some drivers seem to read the EDID data of the display.

    Some drivers seem to have a config panel.

    Providers include AJA and BMD.

    See 3rd party for instructions.

Question: How do we check what we're seeing in PrPro?

Here is a simple visual test to verify that you're not completely off. It works for all connected SDR displays regardless of how they're connected.

The most critical point in SDR display setup is the black clip level.

Use PLUGE (picture line-up generation equipment) on the color bars in Premiere for sanity checking. (Or similar test patterns.)

• If you can't see the 2% or 4% steps, then you're clipping shadow details. If you grade with this setup, the final video will have milky blacks (@4%) on the perfect TV.

Another critical part of display setup is display gamma.

Target a gamma of 2.4 for a dim surround (living room, screening room), and 2.2 for an average surround (office, coffee shop, sRGB)

If grading with too high a gamma, the final video will look washed out on the perfect TV or in the office.

Gamma can be verified visually using a gamma checker test pattern.

White clip level is not as critical. You can be off by several percent without noting the flat whites.

When I say the perfect TV, I mean a reference SDR viewing device in a reference viewing environment displaying video according to the standards.

It's more complicated for cinema and HDR display setups.

The above test patterns must be viewed as ungraded footage in Premiere, as you want to verify the display output from Premiere, not from other apps. Color managed apps can fail this test.

Worth mentioning that your main content should not go outside the 0.0 - 1.0 range in the Premiere scope. Use the video limiter for cleaning up the occasional outlier.

I read through the thread, thanks for taking the time and posting.

I decided to color grade a video on my macbook, upload to youtube and check how it looks on my macbook, iphone and iMac and the results looked the same - just how it looks when I create in premiere. They even look the same in Chrome and Safari (slight differences but not enough to complain), and even quicktime.

I understand that I can't control how it looks when people view the video on different browsers/computers/video players, and I understand that editing for "true" color should not be done on an standard computer screen. Not disputing those aren't true.

I think that test I did proves that the thread above doesn't address the issue I have. Everything looks how you'd expect when working on one machine but try it on my iMac and the issue starts. Remember that the footage fresh from the camera looks the same when viewing it in finder on my macbook and iMac. It's only when I bring it into premiere on my iMac that the color gets automatically adjusted and saturated.

The search continues