Camera Raw Display Brightness Flickering on Mac Studio + Pro Display XDR

Environment:

APPLE Pro Display XDR with ↓

1. MacBook Pro M2 Max 3669 MHz (12 cores) / 96GB RAM / 8TB SSD
2. Mac Studio M2 Ultra 3671 MHz (24 cores) / 192GB RAM / 8TB SSD

- Mac OS Sonoma 14.5 (latest version)

Photoshop 2025 (26.5.0 latest version)

Lightroom Classic (14.3 latest version) Build［202504141032-10373aad］

Adobe Camera Raw (ACR) Core Shared Between Both

Display Color Profile: Default (Display P3 / Apple-managed HDR)

GPU acceleration: Enabled and disabled for comparison

Issue Summary:

When editing RAW images using either Adobe Camera Raw (via Photoshop) or Lightroom Classic (Develop module), the preview display alternates between a visibly darker image and the correct brightness during slider adjustments. This flickering undermines the accuracy of tonal evaluation and disrupts professional editing workflows.

Expected Behavior:

The preview image should remain stable and accurate in brightness.

Adjusting sliders should update tonal values smoothly without abrupt shifts in perceived brightness.

Actual Behavior:

Upon loading a RAW image, the initial preview appears noticeably darker or flatter than expected.

As soon as a develop slider is moved (e.g., Exposure), the preview suddenly brightens to its correct rendering.

Adjusting a second slider may cause the preview to flicker again, reverting to a darker state before returning to normal.

This flickering occurs repeatedly, with high consistency.

The issue appears in both Photoshop and Lightroom Classic, strongly suggesting it originates in the shared Adobe Camera Raw rendering engine.

Steps to Reproduce:

Connect a Pro Display XDR to a Mac (Mac Studio or MacBook Pro).

Open any RAW image in Lightroom Classic or Photoshop via Camera Raw.

Observe that the image initially displays with lower-than-expected brightness.

Adjust any develop slider (e.g., Exposure +0.10) — preview jumps to correct tone.

Adjust another parameter — flickering resumes.

Notes & Hypothesis:

This issue has persisted since 2020, when the Pro Display XDR was first released.

I initially assumed it would be resolved in future Adobe updates, but the behavior remains unchanged through multiple major versions.

This does not occur on other professional displays (e.g., EIZO) using ICC-managed SDR workflows.

The issue is not visible in screenshots — taking a screenshot during the "darker preview" still captures the correct (brighter) version.
This implies the flicker occurs at the display rendering level, not at the image raster level.

I can provide a screen recording video if needed to demonstrate the issue.

Severity:

High for any user doing professional color grading, printing, or tone-critical photo editing.

Visual instability makes tonal judgment difficult and undermines workflow confidence.

Suggested Fix:

Investigate rendering and tone mapping order when Camera Raw operates under HDR-capable displays such as Pro Display XDR.

Provide user-facing toggle or preference to disable HDR tone mapping for preview.

Force preview rendering refresh upon file load without relying on parameter adjustment.

Ensure consistency between initial preview tone and updated preview upon slider change.