Macbook M1 Air with HDR monitor: 30 bit option greyed out in Photoshop

[bobdefcon]

I have Macbook M1 Air with 8GB and 256SSD attached to a BenQ SW271 in HDR mode. MacOS recognizes and activates the monitor correctly as a HDR display, but Photoshop (current 2022 version) shows the 30bit display option greyed out. Is Photoshop able to support the full color spectrum of my SW271 on the M1 Macbook? How?

[Bob_Hallam]

Use SwitchResX to test and see if the monitor that's connected is displaying billions of colors mode i.e. outputting a 10-bit signal. That's probably the issue.  Check to see which of the cables used supports the highest bit depth and make sure that is what your using.  Hopefully that helps!

[bobdefcon]

Hi Bob, thanks for your advice. Fortunately, the cable is not an issue and SwitchResX shows a billion colors. Unfortunately, Photoshop does not. Any idea where to look?

[Bob_Hallam]

Try this: in PS prefs / general. Click Reset Preferences on Quit and restart Photoshop 

[Adam Jerugim · Accepted solution]

The following things need to be set in order to view HDR on Mac:

1. In System Prefs > Displays choose a Preset that supports HDR (P3-500 or greater, I'm using P3-1600)

2. In Photoshop go to Preferences > Technology Previews > and enable Precise color management for HDR display

3. Quit and re-launch Photoshop and should be able to see HDR images displayed correctly to screen

[sacb0y]

How is this done on windows? 

[ucphotog]

This answer does not seem to be applicable to the M1 Mini. There are no "presets" in the "System Prefs > Display" section. I assume you mean for the ICC profile? I really didn't see any evidence of a preset for the M1 Mini.

That said, I have copies of Photoshop 2020, 2021, and 2022 on my M1 Mini. Both 2021 and 2022 gray out the 30 bit option. Nothing I have done so far will change that. They also display a 10 bit PSD of a gradient with lots of steps.

However, the 2020 version does NOT gray out the 30 bit option. And it displays the 20 bit PSD of the gradient quite smoothly.

So, this shows that Photoshop *can* enable 30 bit for a Mac M1 Mini. However, the newer versions of Photoshop cannot do it.