Last night, after taking several hours of Ha data on NGC1499 (California Nebula), I point my scope to a random patch near NGC1499 and take a 600sec image with L filter. Originally I was trying to see the faintest star but found an interesting galaxy in the picture.
After plate-solving and cross referencing with SkySafari, I think that galaxy is UGC 2885. I also found a discussion at CloudyNight.
UGC 2885 is 331M light years away from us but it is not the faintest galaxy in the picture. There is a tiny PGC 213253.
SkySafari said it is a 17.1m galaxy... I am surprised this kind of object can be easily detected in a single frame image (without stacking or processing)...