A little comment to the message: The following text was generated with help of an AI, because I’ve got frustrated trying to solve the issue myself and ran out of strength; I apologise for that. Yet it describes the problem well:
Dear ChimeraX/ArtiaX developers,
I would like to report an issue with volume rendering quality on macOS that appears to have been introduced in ChimeraX versions 1.7 and later, and that affects ArtiaX-based tomography workflows.
System details
macOS 26.0.1 on Apple Silicon (M2 Pro; RAM 16GB)
ChimeraX 1.6.1 (works correctly)
ChimeraX 1.7–1.10.1 (affected)
ArtiaX 0.3 (works correctly)
ArtiaX 0.6 (affected)
Native ARM64 ChimeraX binary used (not via Rosetta)
Tested both on the built-in display and external 4K monitor
Issue summary
When displaying reconstructed tomograms (binned 4x to pixel value 10A) in ChimeraX 1.7 and newer, the volume appears blurry, pixelated, and significantly lower in resolution compared to Fiji or ChimeraX 1.6.1. The same tomogram, same hardware, same display settings, and same scaling factors show correct high-quality sampling in ChimeraX 1.6.1 + ArtiaX 0.3.
In contrast, ChimeraX ≥1.7 + ArtiaX ≥0.6 consistently produce a downsampled-looking rendering.
Troubleshooting performed
To rule out common macOS/Qt/HiDPI issues, I have tested:
Forcing HiDPI mode (QT_ENABLE_HIGHDPI_SCALING, QT_SCALE_FACTOR, etc.)
Launching via arch -arm64
Removing and reinstalling ChimeraX completely (including preferences)
Disabling external 4K monitor scaling
Resetting ChimeraX user settings
None of these affected the outcome.
Only reverting ChimeraX to version 1.6.1 restores correct rendering quality.
Behavior differences observed
In ChimeraX 1.6, tomograms appear crisp and match Fiji’s display quality.
In ChimeraX 1.7–1.10.1, the same tomograms appear visibly blurred and pixelated.
The command graphics quality high or similar parameters appear unsupported or ineffective in newer versions.
ArtiaX toolbar loads but seems to use lower-resolution textures for slice volumes.
This strongly suggests a rendering pipeline change around the transition from ChimeraX 1.6.1 → 1.7 that affects ArtiaX’s volume display on macOS (possibly due to Qt scaling, offscreen framebuffer size, or texture sampling changes).
Request
Could you please check whether:
ArtiaX 0.6 is triggering half-resolution internal textures on macOS?
The new rendering pipeline introduced in ChimeraX ≥1.7 affects HiDPI texture sampling?
There is a fallback path on macOS ARM that reduces framebuffer resolution?
Any configuration options can restore full-resolution sampling?
To illustrate the difference between the two options (ChimeraX 1.6 vs 1.10.1) I have included the snapshots from two different M2 MacBooks running two different versions of ChimeraX/ArtiaX combinations; the tomogram file, tomogram optical slice position are the same, the screen magnification and the regions displayed are very similar.
Thank you very much for your work and for looking into this.
Best regards,
Yaroslav