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What is HDR, anyway?

(www.lux.camera)
791 points _kush | 3 comments | 14 May 25 12:46 UTC | HN request time: 0.001s | source
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the__alchemist ◴[14 May 25 13:43 UTC] No.43984458[source]▶
So, HN, are HDR monitors worth it? I remember ~10 years ago delaying my monitor purchase for the HDR one that was right around the corner, but never (in my purchasing scope) became available. Time for another look?

The utility of HDR (as described in the article) is without question. It's amazing looking at an outdoors (or indoors with windows) scene with your Mk-1 eyeballs, then taking a photo and looking at it on a phone or PC screen. The pic fails to capture what your eyes see for lighting range.

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eschatology ◴[14 May 25 14:04 UTC] No.43984701[source]▶
Yes but with asterisks; Best way I can describe it:

You know the 0-10 brightness slider you have to pick at the start of a game? Imagine setting it to 0 and still being able to spot the faint dark spot. The dynamic range of things you can see is so much expanded.

Early HDR screens were very limited (limited dimming zones, buggy implementation) but if you get one post 2024 (esp the oled ones) they are quite decent. However it needs to be supported at many layers: not just the monitor, but also the operating system, and the content. There are not many games with proper HDR implementation; and even if there is, it may be bad and look worse — the OS can hijack the rendering pipeline and provide HDR map for you (Nvidia RTX HDR) which is a gamble: it may look bleh, but sometimes also better than the native HDR implementation the game has).

But when everything works properly, wow it looks amazing.

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1. kllrnohj ◴[14 May 25 14:45 UTC] No.43985176[source]▶
> You know the 0-10 brightness slider you have to pick at the start of a game? Imagine setting it to 0 and still being able to spot the faint dark spot. The dynamic range of things you can see is so much expanded.

Note that HDR only actually changes how bright things can get. There's zero difference in the dark regions. This is made confusing because HDR video marketing often claims it does, but it doesn't actually. HDR monitors do not, in general, have any advantage over SDR monitors in terms of the darks. Local dimming zones improve dark contrast. OLED improves dark contrast. Dynamic contrast improves dark contrast. But HDR doesn't.

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2. eschatology ◴[14 May 25 15:04 UTC] No.43985400[source]▶
My understanding is that on the darker scenes (say, 0 to 5 in the brightness slider example), there is difference in luminance value with HDR but not SDR, so there is increased contrast and detail.

This matches my experience; 0 to 5 look identically black if I turn off HDR

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3. kllrnohj ◴[14 May 25 15:24 UTC] No.43985671[source]▶
You may have a monitor that only enables local dimming zones when fed an HDR signal but not when fed an SDR one, but that would be unusual and certainly not required. And likely something you could change in your monitors controls. On things like an OLED, though, there's no difference in the darks. You'd see a difference between 8bit and 10bit potentially depending on what "0 to 5" means, but 10-bit SDR is absolutely a thing (it predates HDR even)

But like if you can't see a difference between 0 to 5 in a test pattern like this https://images.app.goo.gl/WY3FhCB1okaRANc28 in SDR but you can in HDR then that just means your SDR factory calibration is bad, or you've fiddled with settings that broke it.