30bit color Broken in PS:CC, working fine in LR:C though

Forum|Forum|7 years ago
July 16, 2019
10 replies
992 views

The 30bit colour setting in Photoshop is not working.
30bit is definitely working in Lightroom however.

I am using a 30-bit display.
30-bit is enabled in the GPU drivers.
30-bit is enabled in the Photoshop settings.

16-bit RGB test gradient files are buttery smooth when viewed in Lightroom.
The same test files display obvious 8-bit banding when viewed in Photoshop.

Does anybody know how to fix this? Its bizarre that Lightroom is working with 30bit with no issues but Photoshop won't work with 30bit at all.

I've tried using the Adobe support chat bot, but that was ...comical.

OS: Windows10 Pro 64-bit v1903
GPU: Radeon VII with driver 19.7.1
Monitor: Philips 328P6AUBREB 32" WQHD 4MS HDR IPS LED (connected by DP)
Photoshop CC Version: 20.0.5 20190605.r.83 2019/06/05: 1206907 x64
Lightroom Version: 8.3.1 201905241238-dcd7e2de

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D Fosse

Community Expert

Lightroom doesn't have 30 bit support, never had. It uses dithering.

But no, I can't get it to work either at this time (it has worked before). It's either Windows or NVidia.

OSMIUM ImagesAuthor

Participant

I'm not using Nvidia. Windows broke something maybe?

The strange thing in Lightroom is that the banding is visible in the Library module but not in the Develope Module.

Then next question would be, why isn't Photoshop using 24bit dithering when working with 48-bit images? Is it disabled by default?

T

Test Screen Name

Legend

The fact that Photoshop shows banding and Lightroom doesn't, even though Lightroom has no 30 bit support, suggests an idea.

You don't see banding in Lightroom because dithering does work. Why isn't Photoshop dithering? Perhaps because it believes it has 30 bit display, while something is choking what you see to 24 bit. So maybe the problem is downstream of Photoshop (in the driver, monitor or hardware). Look for other tests...