[pmrid (Peter)]

Originally Posted by icytailmark

i am looking at buying a electric focuser for my c14. I have been trying to image mars but everytime i turn my focus knob i lose mars off the center of my camera.

http://www.myastroshop.com.au/produc...sp?id=MAS-051C

Would this be a good focuser?

The JMI line of electric focusers is good. I have 2 of them and can report that they work well and are easily controlled from the PC.
The thing about these focusers is that you don't need a great deal of travel in the drawtube since the coarse focus is done with the standard SCT focuser. Set the drawtube to a mid-point and get your rough focus set for there, then don't touch it again.
The problems can occur where you use a reducer - the standard Celestron .63 reducer is designd to screw onto the rear cell of the scope. That means you can't put a focuser like this onto the scope.
What you need is a focuser that can accept a reducer in the end of the drawtube so it moves with the drawtube - i.e. you maintain a precise and constant back-focus and stilla are able to screw the body of the focuser onto the rear cell. Moonlite make a line of focuser with the ability to accept a reducer like that.
Peter