Hi, Sorry for the long unanswered post,

I was still still using version 3.20 during all that time. I tried again with your most recent version (3.544). I am definitely sure that the tracing behaviour is different in the most recent versions. Tracings with recent vaa3d versions explore a much larger region, and often end finding regions that are way out of the initial tracing. Here is a quick example, but it is very easy to reproduce in many of my stacks. Stacks are coming from 2p in vivo or in vitro recordings, and are a bit more blurry and noisy than confocal stacks. However, it has never been an issue in v3.20

I hope you can help with this issue, that prevents me from upgrading to more recent versions.

Thanks

Antoine