Gamma Bug Lightroom Classic 12.0.1

[Gabriele Santucci]

I think I found a bug on the latest version of Lightroom Classic 12.0.1

When you have a photo without modifications if you use the before/after key (shortcuts " \ " on keyboard) the program will remove the range from the photo. Shadows and blacks lose information.

This problem is also there when you start editing the photo and use this shortuts.

The application has this bug with both calibrated and uncalibrated monitors.

This bug also exists when viewing the photo full screen in the development module with the F key.

I think it's a bug that doesn't act on the photo because when you export the photo and upload it to a website or social media it has no defects

See attached video.

Has anyone noticed the same bug?

My device is a Mac Studio running macOS Ventura 13.0.1
MSI Summit MS321UP monitor
Calibrator: datacolor spayderx

[TheDigitalDog]

I can't replicate it on my Mac. Same OS and version of LR. 

First, try disabling GPU in the preferences (Performance). Any better?

If not, recalibrate and build a new ICC display profile; the old one might be corrupted. If you are using software/hardware for this task, be sure the software is set to build a matrix, not LUT profile, Version 2, not Version 4 profile.


Also see: https://helpx.adobe.com/lightroom-classic/kb/troubleshoot-gpu.html

If the GPU and display profile isn't causing the problem, see:
https://helpx.adobe.com/lightroom-classic/kb/lightroom-gives-error-preview-cache.html