Quote Originally Posted by Richard Asarisi View Post
But under #1 if I start at 3 sec won't the star be blown out and over exposed? So I cut the top off?
Probably not, but even if it does, it will then decrease the exposure time for the actual guiding, or it will choose a fainter star. Even if the guide star is a little bit saturated at minimum exposure time (rare), it usually will guide just fine.

Most have more trouble getting a good guide star at all than saturating guide star. And you can very probably decrease the minimum guide exposure time from 1 second--I run my SBIG guider at 0.5 sec exposure all the time.

The main thing is to prevent frequent need to use maximum guide exposure time to find a star. Unfortunately, that's just what will happen if initial guide time is set to the minimum. It will frequently fail to find a star on the first try, then it will go immediately to the maximum guide exposure to try again.