Thanks Dick!,
Ok that sounds like a pretty good way to do it...asl long as it can continue on to the next object in the event I want to image another object later on. But typically my photometric runs go from horizon to horizon, all night long. So this should work the vast majority of the time.

I am going to download the eval soon, so I want to make sure I understand a little more about how things work.



Quote Originally Posted by Dick Berg View Post
Hi Russ,

Welcome to the world of ACP!

Here's one way to get what you want. You could calculate the "horizon" that corresponds to 2 airmasses (it'd be about 30 degrees) and then set the "Min.elevation" in the ACP/Prefs/Telescope tab to that elevation. Then when the telescope runs into that horizon limit in the West, it'll stop (if that's the end of the script) or go on to the next object.