[JohnH]

I am looking for recommendations re automating focus on my 127 ED Triplet, I could fit a robofocus to the current focuser or purchase a complete new moonlight unit. I do not have a large heavy CCD at present but I do have ambitions - an I think the focuser could move with me to a future scope if I choose the right one....

The reason I am interested in doing this is the need to make (small) focus adjustments to get best focus with each of the individual LRGB or Ha-Oiii filters in the automated sequences I use. It would be great to be able to focus each filter once and then have the unit be able to return to the correct spot automatically thereafter so I really need something robust that stays accurate after many cycles, even better if these focus positions can be found automatically also.

At present I tend to use LRGB or Ha-Oiii in loops to ensure that I have some useable data in the event clouds roll in rather than 16xL then 16xR etc.

What is recommended - L focus, R focus, G focus, B focus seems a little heavy on the focuser so perhaps some compromise is usual?

Any views or experiances (eg is temp compensation required) with automated focusing pros/cons and recommendations are welcome...