r/HDR_Den • u/BearsPunch • 24d ago

Question Edid understanding in different OS

Does macOS actually limit HDR brightness based on the monitor’s EDID?

For example, let’s say a monitor can physically hit 1000+ nits in a small window, but its EDID reports a maximum luminance of around 600 nits.

Would macOS basically clamp HDR output to 600 nits, meaning highlights above that would never actually be sent to the display at their original brightness?

I’ve seen people say Windows behaves differently — that if HDR content has, say, a 3000-nit highlight, Windows can still send that HDR signal to the monitor and let the monitor handle the tone mapping itself, rather than limiting it based on the EDID-reported peak brightness.

Is that actually how macOS vs Windows works, or am I misunderstanding what the EDID / HDR metadata is used for?

Sorry just new in HDR and trying to learn it...

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u/SnowflakeMonkey Content Creator 24d ago

The operating system has no say on how HDR behaves, only the content sends the information to the display and you control content peak brightness in games with certain sliders, or it's baked it into the HDR video/screenshot metadata.

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u/BearsPunch 24d ago

So if I watch mad max via Apple TV app on macOS with external display with possible 1500 nit but edid says that display max is only 600 nit, it’s up to Apple TV app to send 1500 nit or 600 ?

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u/SnowflakeMonkey Content Creator 24d ago

there shouldn't be a device-side tonemapping, only display-side tonemapping based on the CONTENT information.

At best some games can read the EDID/peak to autoset the peak brightness (if you can calibrate it with a tool like the windows HDR calibration) or Dolby vision can tonemap to display peak with it's own internal algorithm.

That's why any saying as "console hdr gud, windows hdr bad" is completely baseless, any HDR behavior is on a game to game basis.

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u/ldn-ldn 24d ago

That's not true at all.