Have you been affected by this Gamma shift bug when exporting video?

I think this is the closest explanation to the problem but a couple of minor details in the problem should be pointed out. The original gamma that led people into calling it the quicktime gamma shift was a similar problem from our history that the original Apple displays before the was any HP/Microsoft coalition coming the the sRGB standard of gamma 2.2 ( approx ) Apple display were using gamma 1.8 - so the difference was way off back then. Now coming into the problems we have now - Color Sync is the problem but not exactly as was explained ( but really close ). The math is assumed By Apple and applied on the fly to a color managed workflow as described but the value of 1.96 is what Apple assumes is the encoding from linear to non linear ( camera gamma ) but in almost all devices and cameras ( the rest of the world ) the gamma encoding math is assumed to be 2.2 - This is where the difference and math problem arises. Typical math with 2.2 Suppose we have a camera that uses a gamma value of 2.2 for encoding (γ = 2.2). 1. Gamma Encoding (Camera): • Let's say the camera captures a pixel with an original linear light value of V_in = 0.5. • The gamma encoding operation is: V_out = V_in^γ = 0.5^2.2 ≈ 0.2176 • So, the camera encodes this pixel with a value of approximately 0.2176. Then in the display gamma decoding ( for your monitor ) • Now, we want to correctly display this encoded pixel value on a monitor. We need to perform the inverse operation. • The decoding equation is: V_out = V_in^(1/γ) = 0.2176^(1/2.2) ≈ 0.4999 The monitor will display this pixel with a value of approximately 0.4999 ( which is the .5 linear we started with ) This process ensures that the image is correctly displayed, compensating for the gamma encoding applied by the camera. This correction is crucial for the image to appear visually accurate to human observers. Now if Apple uses gamma 1.96 for the gamma encoding to a file as it does on the fly whenever a file is going through Apple colorsync. The display encoding math will return a different result - the V_out = V_in^(1/γ) = 0.2176^(1/2.2) ≈ 0.4999 in this equation using 2.2 we get the 0.2176 but using 1.96 we get 0.2570^ (1/2.2 ) = 0.5392 So it appears brighter at the display function. The compensation for that difference is calculated in the Davinci Resolve Resolve band-aid of rec709-a and Adobes compensation LUT. And as explained both software have the ability to let you grade by seeing the colorsync version in it's source monitor. What wasn't discussed in the video is the other problem with colorsync using NCLC tags for viewing video files. And that for some unknown reason ( can't find out why ) NCLC tags have no actual definition for gamma 2.4 even with it being the standard for broadcast gamma as in the BT1886 rec709. This part was a bigger problem in Resolve because using the output of rec709 gamma 2.4 the file would be tagged 1-2-1 which Applesync reads a typical tagging of a rec709 gamma 2.4 file )( 1-2-1 ) as the following: Color Primary - "ITU-R BT.709" Transfer Function - "Unspecified" Color Matrix - "BT709" So when the display transfer function is unspecified the inverse they apply is an inverse of the same badly assumed camera display function of 1.96. So it's even worse. Premiere didn't have this problem because it tagged rec709 as 1-1-1 and if you use the Resolve rec709-a it also retags the file to 1-1-1. I have to hand it to you guys though - your whole explanation is the closest I have seen to date. Great job explaining Kevin

OMG finally an explanation!! no more QT gamma correction when exporting from Premiere!

Great job breaking this down. This has been one of the top questions for new video editors for so long. I remember my early days struggling with this.

Thank you both for this! Kevin you rule! Thanks for this great video

Great explanation!

Well, now I'm glad youtube repeated repeatedly notified me about this video. Google knows dam well how many times I've tried to research color space glitches like this. I'll be basing on 2.4, not 2.2 "middle ground" as I'd rather imagine seen by someone as flater and unsaturated then as oversaturated with too much contrast.

Thank you guys !! this truly helped me !!

Thank you! This is so helpful.

THANK YOU - After years I do now understand and can better deal with it !! - GREAT !

You are heroes, very technical heroes

Finally! Thank you so much.

Thanks for this!

You can also make sure you are monitoring in the right color space if you go to display settings and change your display to view in HDTV Video (BT.709-BT.1886). Make sure your pipeline is still correct but this will add another layer of security that it is working correctly. This may only work well with the pro lineup but it is possible.

I wish Apple would update the gamma setting for Rec709 to assume BT.1886.

I can't say thank you enough for this... I have been haunted by this for years.

So basically Apple is behaving like a baby.

Thank you

On the other hand, if you are using Windows and say, Davinci Resolve, and that is not a small section of the video making population, and you grade a video till it looks good on your colour critical NEC monitor, but then upload it to Vimeo, or transfer it to your iPhone, the result looks desaturated and lacking contrast. Mac users are locked entirely into their own ecosystem, grading on Mac, viewing on Mac, iPhone, iPad, and most likely see no problem. But editing on Windows, viewing on iOS, frustrating to say the least.

Great job Kevin this is totaly a game changing video. Apple always have to do it the other way and still everybody is buying it i can not understand

Very good explaination. Thank you for putting this together. I got one questions. HDR on or off on a HDR-display?

I think Apple has kind of left Rec.709, and moving on to 2020 and 2100, HDR, HLG etc. What are you thoughts on that?

Solution at 17:30

So I have a 2021 M1 Max MacBook and the way I edit with Premiere is one large 27in display as my primary and the macbook display right next to it as the fullscreen preview display via the mercury transmit thing...if i do what you suggest and change my viewer gamma to 2.2...the macbook display does not change...and what seems to match best is 2.4 like it was originally...so its kind of confusing that the macbook monitor will always show 2.4 essentially even though macos will always make it 1.96....should i just fullscreen the program monitor on my macbook display instead?

Just to be clear? For the best (widest-compatibility) solution for resolve would be 1. enabling the use Mac display color profiles for viewers 2. Setting timeline color space to 2.2 or 2.4 or scene 3. Setting output colorspace to 2.2 Correct?

Why does this not happen in FCPx?

Thanks for this explanation ! Any problem on FCPX ?

I have been struggling to fix this exact issue with my client as we always had different views every time I threw color grading preview via Google Drive to them. They always said the image is too bright and the skin color is a little bit weird, while everything is look normal to me on my MacBook Pro M1 Max. I began to lose my mind and we have no idea which version of it will be displayed when exported as DCP and screened via the theatre's Doremi server projectors...

AMEN :)

@kevin.stiller what are your thoughts on the Adobe qt gamma lut? Also, since iPhones are dci-p3, I assume that grading using the standard MacBook XDR profile would be the best option? Or better to just set the monitor profile to to rec 709 and continue that way? Thank you

Fantastic video! I currently don't have a reference monitor. For someone working in After Effects, how would you go about solving this issue?

Another note, my samsung galaxy phone has a "video enhance" feature.. it looks like it just boosts the gama and saturation, on a display that already pushes its limits. I keep it off cause it blows out bright saturated colors, resulting in a loss of detail. Some people like that look, and good for them, they have the option to turn it on, I'm just thankful it isn't baked in. Apple could one over Android by updating to assume 2.4 as default then give "video enhance" options to either revert back to legacy mode, keep it at the new standard, or push the saturation and contrast.

What about FINAL CUT ?

Is After Effects color managed?

Thank you for this excellent video., it's is a very interesting insight. But the thing I often hear is that the answer to the problem is having a reference monitor. I have one, it's calibrated for BT1886 rec709, but when I export my work in Resolve the result is still being reproduced 'different' when I watch it in a color managed app on a Mac with a Mac P3 display than on my reference monitor. The issue of Color Sync interpreting rec 709 differently than my reference monitor is still there. So what am I missing here? In what aspect is it the answer to the problem?

Semi newbie here: Does the Premiere QT Gamma export LUT fix fit in somewhere to the topic being discussed here?

So what happens if we switch the display color mode to 709 1886, wouldn't that fix the issue?

is this true for all monitors, or only for apple ones? For example, what about a mac studio with third part display? Because with this setup I see no difference for the same video un mac and pc in VLC players and da vinci viewers, but enabling mac display color profile for viewers in da vinci the only corresponding image result da vinci and quicktime for ONLY rec709A export. For broadcast delivery could be a good idea calibrating a monitor in rec 709 gamma 2.4 profile to avoid problem?

Very easy to understand this way! The only thing i'm still not really sure about is the assumption that grading in 2.2 is "safe". Is the iphone doing the same conversion with chrome/safari/youtube? because if so, there are a so many people (at least in my surroundings) that are viewing my exported videos on apple devices. which means a horrible conversion for the majority. I might consider to just cut my losses and grade in rec709 1.96. or maybe even p3.

So the real problem with this shift is color correcting and grading based on a faux color shift, then getting a surprise later when things come out too dark and saturated. Am I understanding this correctly? My workflow is very simple compared to a Hollywood-style shop. Usually RED log clips, color and edit. So I need to ensure I'm at 2.2 or 2.4 gamma before the color phase or I will color based on the QT issue.

Thank you very much for this ! However, when i change my settings like you propose on davinci, my image becomes way darker, and extremely contrasty (quite the opposite from what you say...?). Also, when i change the output color space, it does not do anything. i can choose any color space, no difference... is there something wrong ? please help :)

So only the gamma Bt.1886 (wich is something close to the gamma 2.2 on LCD's and closer to 2.4 on OLED's from what i found out) is still not available in this editing programs. Haha

@kevin.stiller I have a question for you still. I'm one of the lucky ones who DOES have a reference monitor. However this problem still plagues me because I will grade with clients who love a look in a controlled environment only to panic email me the next day that it looks "washed out" on their iPhone etc. Any thoughts on how to handle this annoying (and recurring) problem? Especially if delivering for web and NOT broadcast? 709-a / Gamma 2.2? What's the latest and greatest?

Nice Video!!!! But where are the links?

I can set my internal display colour profile to Rec. ITU-R BT-709-5 even on a simple MacBook Air m2. Doesn't this solve the issue? Why should anyone grade Rec709 on a P3 profile?

T H A N K Y O U It's been years of pure pain and frustration T H A N K Y O U

The export looks washed-out but on the other hand video on Netflix (Safari) looks too dark. On a M1 MacBook the default Display profile is LCD. Switching to P3 shows how much of the darker picture information has been lost. Seems to be the same bug?

Good approach, but it could have been shorter!

Still using gamma 2.2 in grades and am fine with it.

Unbelievable ...

And FINAL CUT?

It’s the premiere viewer that’s the problem. Resolve doesn’t have this issue. If you render footage from resolve, and bring it into premiere, and render it out of premiere, it will look identical to what you rendered out of resolve. And that will look right on web, phone, TV, computer, etc. it’s premiere that is not showing an accurate image.

I can tell you why this is happenning in Davinci Resolve, I know the reason well - it is because 1/ Davinci is shipped NOT COLOR MANAGED by default on Mac platform (you have to configure settings for color management to start working) 2 Davinci refuses to mention this info in their famous 4000+ pages manual. NO instructions given there at all on how to setup Davinci to work with Mac color management on a GUI display. So if you setup Davinci properly, there will be zero issues with colors not matching on export.

too long of a video, what's the fix? Gamma what?

ahh yes. classic apple bs. Like their bad macbooks wich have the same hardware issues over 4 generations and the dont want to fix it. ah yes...

Gamma 2.4 is WRONG for average consumer because PC displays and consumer TV sets are set to gamma 2.2. That why only PROs who edit for CINEMA and TV broadcast use gamma 2.4 - IT IS NOT a standard for consumer displays

THe video is exceedingly diluted and over-complicated. Simple facts are - . THere is no quicktime bug in current Mac OS, and NEVER WAS! Indeed long time ago Quicktime on mac displayed videos with a slightly brighter gamma for more pleasing presentation on the average mac monitor of those days. Thats ancient history now and they stopped doing it 20 years ago! Now the issues described in this video are 100% related to video editing software settings. E.g. Davinci IS NOT COLOR MANAGED on Mac platform BY DEFAULT! You need to dial in proper settngs for it to show proper colors on a Mac GUI display. If you set up Davinci Properly you will have perfect 100% match on export, upload to KZfaq, etc. He gave himself away when demonstating the bug he only mentioned Premier and Davinci - 3rd party apps. Apple’s own Final Cut works fine out of the box, not requiring any twiddling.