Uneven Local Dimming in HDR on MacBook Pro M3 Mini-LED Display

[Zupi]

I've noticed that in dark scenes, certain areas appear much darker than others, like shadows within the dark scenes, and it looks unnatural. Is this a characteristic of the Mini-LED display, or could it be a software/hardware issue? If you look closely at the images, you’ll notice these darker sections that stand out from the rest:

 

[blufrog]

What happens if you paint a uniform black screen with perfectly black pixels?

I'd suggest this shows how good the Mac display is, and the source is not perfectly black across the entire frame.

 

[galad]

The mini-led display dimming zones are quite big, so that's the best it can do in that situation.

 

[Zupi]

What happens if you paint a uniform black screen with perfectly black pixels?

I'd suggest this shows how good the Mac display is, and the source is not perfectly black across the entire frame.

When I open a video with a completely black background on YouTube, everything appears black, and I haven’t noticed any backlight issues. However, when watching HDR video locally or on Netflix, if there’s a scene where an actor is holding a lit candle in the dark, it seems like the local dimming algorithm struggles and doesn’t work properly. A circle with an irregular and unnatural shape forms around the character; it’s bright within that circle because of the candle, and dark around it. However, even that dark area isn’t well-dimmed, with small parts becoming illuminated, looking like cracks in a cave that emit light. In some scenes with the candle, the entire screen seems to flicker due to the candle, while in SDR mode, this doesn’t happen, likely because the local dimming algorithm is inactive or constant.

 

[Zupi]

Or, for example, another scene: the character is in a dark cave, and the local dimming algorithm creates a dark circle around their head, while the rest of their body appears a lighter shade of black, which looks quite ugly, artificial, and unnatural. I can’t recall for sure, but I think that before macOS 15, I hadn’t noticed anything like this; only after upgrading to that version did I start noticing such details.

 

[blufrog]

Interesting. The poster above suggests it could be related to how the backlight is dimmed on the display, but with how you describe the circular pattern around specific features, makes me think it is some artifact of compression or image processing.

 

[Zupi]

Interesting. The poster above suggests it could be related to how the backlight is dimmed on the display, but with how you describe the circular pattern around specific features, makes me think it is some artifact of compression or image processing.

It doesn’t have to be a circle, but the darkened area looks quite unnatural and artificial, as if I painted it over in dark black using Paint, with various shapes. Additionally, since upgrading to version macOS 15, I’ve encountered this issue in Chrome and Firefox while watching HDR videos in youtube, so I’m not sure if it’s related:

https://forums.macrumors.com/thread...es-on-the-edges-of-macbook-m3-screen.2438794/