I made a list-minute decision to come out observing tonight, primarily to catch a maximum of EY UMa. Beautiful conditions, with seeing good and constant through the night. Very nice northern lights, too.
I also did a short test to see if I could figure out what was going on with the “wavy” darks…turns out that turning off the lights eliminates them.
Temperature was 39F, focus 2840, FWHM around 5.