Hi. I have a ASI6200MC and if I shut-off the FITS viewer and am careful about quitting the Preview window after each use and use some binning when focusing / aligning, I can get by barely. Any slip up and it crashes. Even when careful, a crash is likely after several hours of continuous operation. I have a RPi4 with 4GB and an RPi4 with 8GB. I tried loading the 8GB with the arm64 raspbian OS (beta) and compiling Kstars/EKOS from scratch to get a 64-bit version to determine if the extra memory access alleviates the problem. I have run into a showstopper with that approach ("Exposure failed after 3 attempts") so I don't know if it would help. Has anyone successfully built an arm64 version? If that solves the problem, that seems like the best way to make all users happy (those that don't need it and want to stick with their current Raspberry and those that want it enough that they would not mind springing for an 8GB Raspberry and using the 64-bit OS.

Anyhow, for the here and now, perhaps a software binning option just for the FITS Viewer display (i.e., independent of workflow image capture) is another alternative?

It is definitely worthwhile to provide an option to release all FITS Viewer image related memory once the image is displayed. That should save having to kill the previewer and should also allow one to keep the FITS Viewer option on.

I am new to astrophotography having recently retired and taken it up as a hobby. I am both amazed and thankful for KStars/EKOS/INDI. Big sensor, however, are only likely to become more prevalent and need to be addressed, the sooner the better (IMHO).