Dear Hugh, I read that you work in alt-az mode to avoid the effects of atmospheric dispersion. I’d be interested to know how you do this. I have an AZ-EQ6 Mount but haven’t tried the AZ mode. I normally guide on a different star to the target. Does field rotation interfere with your guiding? Do you have more difficulty synchronising your telescope to your planetarium software? I’ve been put off trying AZ mode because I had heard that it’s “go to“ function was not so accurate.