Hi Peter,

I have a CEM120EC2 as well - for about 8 months now. I see that we are shooting with the same OTA at the same focal length. Do you mind sharing your settings in the options tab? While I'm at a lowly 500 feet above sea level, my guiding very consistently issues pulses to the mount and while my guiding can be <.5" it is often greater than that and approaches 1". While my stars are still round, there are frames where the bloat is visible when blinking a nights images. As a result I'm constantly fiddling with the options settings trying to improve performance. One thing I notice is that you have your guide camera set up for 1x1 binning. I've gone back and forth and am currently at 2x2 and getting ok results.

Thanks for any thoughts you care to share - Fred