HDR flickering MacBook Pro Retina XDR

Hello,

I started using Infuse on my new MacBook Pro with M3 Pro and noticed something with HDR movies : they sometimes flicker. But it’s not a “blackout flicker” like I could read elsewhere on the forum. It’s like if the HDR “data” would not playback nicely. For instance in some scenes only some part of the image will have the flicker effect.
It tends to happen when colors changes on screen, so when the camera changes angle for instance.

Sorry if this is not very clear as I don’t know that much about movie codecs or HDR data stuff.

It’s very subtle but can get very annoying.

Here are some screenshots from slow-mo videos I took using iPhone:
(I can try to upload the slow-mo but they are quite large files)
(Here are some movies but it happens in other movies as well)

1. Geostorm


Here you can see on the left part of the image that the flickering is green.


Here again (I tried to take different frames)

2. James Bond - No Time to Die


Here you can see that the top left part of the image is very bright for no reason (see image below that is some frames after and looks correct)


Normal looking.

3. Seven Sisters


This is what it’s suppose to look like for reference.


Here colors are washed out and have this “green/blue” tint effect.


And here again same weird color effect + bright effect for no reason.

As you can see it’s quite subtle but you can definitely see it with the human eye. It’s quite frustrating to have a beautiful looking image 98% of the time and the rest of it, it flickers killing off the experience of this beautiful MacBook Pro display.

Thanks in advance.

This is not an issue with Infuse, it’s an inherent characteristic of the display panel and it also occurs in the Pro Display XDR and the large iPad Pro. You can confirm this by watching the first episode of the second season of Foundation in Apple’s TV+ app. The black and white scene at the very start of that episode exhibits this greatly.

The cause of the artifact is because there is an inherent delay and imperfect synchronization between the control of the display backlight and the liquid crystal layer. You have probably noticed the following:

When a scene goes from dark to bright, there is a flash, sometimes distinctly green tinted.

When a scene goes from bright to dark, there is a lingering halo, sometimes distinctly red tinted.

Evidently not many people notice or are bothered by the artifact as you’re the first person in years I’ve ever seen bring it up. The cause seems to be two-fold.

One is that there is a delay in the backlight ramping up or down when the colors of the pixels being displayed change significantly from one frame to the next. This “backlight lag” is inherent to all displays that use local dimming. Apple deals with this far better than any other company. Something like my Samsung G8 monitor handles this miserably compared to my Pro Display XDR. There is just inherently a different response time to control the backlight, and to change the liquid crystal layer, and you have to just do the best you can at coordinating these two independent elements with very different physical properties.

The other issue which is the source of the green tint you capture, is more unique to these Apple displays at least based on my testing. I’ve never seen it on televisions that use local dimming, nor on the G8 monitor, etc. We can intuit what’s going on based on the symptoms that I described above.

To give some context, displays that are LED backlit don’t use individual R,G,B LEDs. Instead, most use a blue LED coated with a yellow phosphor to give white. In pursuit of wider color gamuts, display engineers have developed more complex solutions such as GB-r LEDs in the past, and today they may use different phosphor coatings or quantum dots to convert the blue LED light into the appropriate R,G,B wavelength peaks to achieve their target color gamut. Apple’s displays must use some phosphor or quantum dot film to do this as well.

So, what does it mean if we see green when we go dark to bright, and we see red when we go bright to dark? We can conclude with near certainty that whatever compound is producing the red component of the backlight is slower than the green one to respond to changes in the emission of the blue LED.

Therefore, when the backlight ramps up, we have blue from the LED, and the green responds the most quickly, so we for a very tiny moment that you need to record in slow-mo to capture, we have only green and blue light being emitted from the backlight, hence a blue-green tint. Once the red responds, we have white and the artifact resolves.

When we ramp down, the blue light goes down, the green is the most quick to go down, but the red is slower to change, so we have a brief moment where we have the red light emitting still but not as much green or blue, so we get a red tint. The red then responds and reduces or stops its light emission and the artifact resolves.

Apple is almost certainly aware of this but whatever material they’re using in the backlight was probably the best possible option to meet their brightness and color gamut target. This is purely speculation but you could imagine if you were engineering a display, maybe you also considered another material that can do the P3 gamut that doesn’t have this issue, but perhaps it didn’t produce bright enough light with low enough power and heat to meet the XDR requirements, or perhaps it was just too expensive to fit into the product budget.

Sorry to say but, you have good eyes, and you’ll have to suffer for it :slight_smile:

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Damn thanks a lot for this very detailed reply.
I did some research and in fact I actually get the same issue with IINA and even the AppleTV+ app once I converted the MKV to whatever AppleTV app is using.

But yes it’s very faint and slightly noticeable but I think that I am one of the only ones to notice this issue like you said. And in fact it does not appear to be a hardware issue in my machine as other people had the same “issue” and Apple said that nothing was wrong.

I guess I will have to hope that OLED fixes that…

It will depend on what OLED technology Apple will end up using. The QD-OLED panels from Samsung also exhibit a flicker on near-black content on some of their TV offerings. While I’ve never seen this happen on TV’s using LG panels, these suffer from banding on very light grey content (e.g. 10% grey).

Unfortunately, no display technology that’s currently on the market is free of flaws. Hopefully microLED will bring change in the future, but production is still to expensive for now.