Smaller = anything smaller than a consumer grade DSLR. The form factor make the smaller units far more difficult to hold properly while shooting, lack the opti

Smaller = anything smaller than a consumer grade DSLR. The form factor make the smaller units far more difficult to hold properly while shooting, lack the optical viewfinder in most cases, etc. The only thing a person needs for Star trails is a tripod and the sky. Stars start to "trail" generally anything over 500/effective focal length in exposure time in seconds. Built in focus stacking does sound useful if it works well and macro shots are of interest. Hi res modes are fine but it can never make your pixels bigger - bigger pixels of the same generation more sensitive to light so less noise at higher isos. I have canon glass so tried one of their mirrorless cams and found its Ergonomics completely different to DSLRs and personally not in a good way.