When I go from Develop to Library mode my mask shifts away from the subject creating a halo.

[joel59964221]

I edited this image in April and submitted it to a photography contest.   At the time I darkened the background with a mask. I then esported the image without any problem.  However now, in June when I export the same image a halo is created around the subject.  

In Develop mode the image looks normal (no halo).  When I shift to Library mode the mask moves slightly away from the subject leaving a halo.  I cannot find a way to get around this.  

I won a contest with this image and now the contest admin wants a higher resolution image so it can be printed in a poster and place on display.  Help! 

Lightroom Classic 14.31 Camera Raw 17.3.1

Mac Sequoia 15.5

Apple M1 Pro

32 GB Memory

[Claire H. · Accepted solution]

Hi @joel59964221, Welcome to the Lightroom Classic forum! As you may know, Library mode uses pre-rendered previews (compressed JPEGs in Adobe RGB), while Develop mode uses a live rendering engine with ProPhoto RGB. These differences can cause masks to appear misaligned, especially if the image was edited in an earlier version of Lightroom and reopened after an update. GPU acceleration and AI masking updates may also contribute to rendering inconsistencies.

Let's try a few things to troubleshoot this issue:

1. Rebuild the Mask: In Develop mode, delete and recreate the mask. 

2. Force Preview Rebuild: Go to Library > Previews > and choose Build 1:1 Previews.

3. Export from Develop Module: Use the Soft Proofing panel and export directly from Develop to bypass Library rendering.

4. Disable GPU Acceleration: Go to Preferences > Performance and toggle GPU acceleration off. Restart Lightroom and test again.

Maybe try some of the solutions found in this community post: https://adobe.ly/4kMarUu

Let me know if any of these steps help solve your issue. If not, we can move on to the next steps for troubleshooting. I hope this helps! ^CH

[joel59964221]

Claire,
Thank you so much for your response and further clarification of the processes involved. Before reading your note I went ahead and re-edited the original image in LRC using the original settings. Although there are some very minor difference that I can’t explain, the image is close enough to use. I will also follow your troubleshooting advice and let you know how that goes. Thank you…joe