|
Paul,
I added a Feathertouch micro focuser 10:1 knob for my C9.25 OTA (around $140 from memory) then added a Meade motor focuser -> Shoestring Astronomy USB adapter -> PC for electronic focus control.
I love the Feathertouch it looks and works well; most noteably it unexpectedly improved mirror flop by a factor of 2x - 3x. When I used to reverse direction during focusing a star it hoped around fairly wildly in my field of view = Oh oh! After adding the feathertouch focuser the star shifting position during a change from inwards to outwards focusing (or vice-versa) went from horrible to neglible.
The Meade motorfocuser I use with a Bathinov mask to achieve the finest focus. I have found from experience a motorised fine focuser - even a low-end one - is a great thing to have.
So unless your OTA already has a focus lock on the primary - consider getting rid of the standard focuser that comes with your OTA (especially if its a Celestron)!
Matt
|