P: Photoshop 27.8 & later Rendering Artifacts, Exposed Previews and Color Banding

Updated to 27.10.0 and it seems like this issue is not resolved.

Summary

When I convert a 16-bit Adobe RGB (1998) document to Lab Color in Photoshop, highly saturated colors appear slightly duller/desaturated. The issue disappears completely when “Use Graphics Processor” is disabled in Photoshop. This appears to be a GPU/Metal preview issue rather than a change caused by the color conversion itself.

System information

• Computer: 16-inch MacBook Pro with Apple M1 Pro

• macOS: 26.6.2, build 25G83

• Photoshop: 27.9.1

• Graphics processor: Apple M1 Pro

• Document: 16 bits/channel, Adobe RGB (1998), one rasterized pixel layer

• External display: calibrated Eizo ColorEdge CG, connected via USB-C to DisplayPort

• The issue is also visible on the MacBook Pro’s internal display

• Proof Colors is disabled

Steps to reproduce

1. Create or open a 16-bit Adobe RGB (1998) document containing a single rasterized pixel layer.

2. Add saturated test patches with these RGB values:

   • 255, 90, 0

   • 0, 255, 90

   • 0, 90, 255

3. Include a normal photographic image without extremely saturated colors in the same document.

4. Ensure that View > Proof Colors is disabled.

5. Convert the document to Lab Color using Image > Mode > Lab Color.

6. Observe the saturated test patches.

7. Convert the document back to Adobe RGB (1998).

8. Repeat the test after disabling “Use Graphics Processor” in Photoshop’s Performance settings and restarting Photoshop.

Expected result

The color-managed appearance should remain essentially unchanged when converting from Adobe RGB (1998) to Lab, apart from negligible conversion precision differences.

The approximate Lab values of the test colors are:

• RGB 255, 90, 0: Lab 68, 74, 81

• RGB 0, 255, 90: Lab 84, -123, 62

• RGB 0, 90, 255: Lab 42, 29, -93

These colors are within Photoshop’s Lab encoding range.

Actual result

With “Use Graphics Processor” enabled, all three saturated test patches appear slightly duller or less saturated after conversion to Lab. The photographic background, which contains less saturated colors, appears almost unchanged.

When the document is converted back to Adobe RGB, the test patches appear vivid again.

The problem disappears completely when “Use Graphics Processor” is disabled and Photoshop is restarted.

Additional troubleshooting

• Photoshop and macOS are fully updated.

• The problem occurs on both the calibrated external Eizo display and the MacBook Pro’s internal display.

• The external display connection is therefore unlikely to be the cause.

• Disabling only OpenCL, GPU Compositing, and Anti-Alias Guides and Paths does not resolve the issue.

• The 30 Bit Display option is greyed out.

• Converting the same Adobe RGB document to ProPhoto RGB does not produce a visible change.

• Proof Colors is not enabled.

Impact

This makes GPU preview unreliable for color-critical Lab work. Disabling the graphics processor restores correct appearance, but reduces performance and disables or limits GPU-dependent Photoshop features.

Please investigate whether Photoshop’s GPU/Metal canvas renderer applies a different or incorrect display-color transform to Lab documents on Apple Silicon.

I can provide a small PSD test file, screen photographs, and Photoshop System Info if needed.

There are problems in RGB as well. I have attached my example. Both “no GPU” versions look correct. With-GPU in CMYK is obviously riddled with bands, but note the band of saturation in the with-GPU RGB version. Harder to notice but it’s a problem!
 

I updated to the latest version and the result is the same. This problem only occurs when converting RGB to CMYK. Creating gradients and painting is fine.
I had to install an older version of PS to do that, as I had some basic errors ;)

Title

Photoshop 27.9.1 (Apple Silicon): 16-bit Gray Gamma 2.2 documents display severe posterization with GPU enabled; TIFF data and prints are correct

System

Photoshop 27.9.1
macOS Tahoe 26.6.1
Mac Studio M2
Eizo 10-bit display
GPU enabled

Steps to reproduce

Create a new 16-bit Adobe RGB (1998) document.
Draw a smooth black-to-white gradient.
Convert to Gray Gamma 2.2 (or Image → Mode → Grayscale).
Observe severe tonal stepping in Photoshop.

Expected

The gradient should remain perfectly smooth.

Observed

The Convert to Profile preview is smooth.
After the conversion is committed, Photoshop displays strong posterization.
A screenshot captures the posterization.
Saving the 16-bit TIFF and opening it in macOS Preview shows a perfectly smooth gradient.
Printing the TIFF with PrintTool/QuadTone RIP produces a perfectly smooth print.
Converting the grayscale TIFF back to Adobe RGB in Photoshop also displays smoothly.
Disabling Use Graphics Processor completely eliminates the posterization.

Conclusion

This appears to be a GPU/Metal rendering issue affecting Photoshop's display of 16-bit grayscale documents. The underlying image data are correct.

Photoshop Beta – GPU ON causes incorrect color/saturation compared with Camera Raw and GPU OFF

Bug description

Şunu olduğu gibi kopyalayıp Adobe Community'deki Leave a reply alanına yapıştırabilirsin:

I have identified a reproducible color rendering issue in Photoshop Beta when the Graphics Processor is enabled.

The same image is displayed correctly in Camera Raw and in Photoshop Beta when Use Graphics Processor is disabled.

However, when Use Graphics Processor is enabled, the image appears noticeably different, particularly in terms of color saturation and color rendering.

I have tested this several times with different images and obtained the same result:

Camera Raw → correct colors
Photoshop Beta + GPU OFF → correct colors
Photoshop Beta + GPU ON → incorrect/different colors and saturation

The difference disappears when I disable Use Graphics Processor and restart Photoshop.

This makes me believe the issue is related to GPU-based rendering/color management rather than the image file itself or the Camera Raw settings.

Photoshop Beta version: 27.11.0
Operating system: Windows 11
Computer: ASUS Vivobook Pro 16X OLED

I can provide screenshots showing the same image side-by-side with GPU enabled and disabled if needed.

Please investigate the GPU color rendering/color management behavior in the current Photoshop Beta.

Ok, I'll check,

Known bug. IIRC there’s a fix in the latest beta, but can’t recall if it has made it to the production version yet. But it will.

It was the same in the previous version: when converting an RGB photo to CMYK, banding appears in gradient areas. The same photo converts perfectly in Photoshop version 27.5.

Orginal

PS 27.9  Convert to CMYK  - problem gradient

PS 27.5 Convert to CMYK  - gradient Ok