Running out of coarse focus on SCT?

[wysiwyg (Mark)]

Hey Guys,

On recent outings I have discovered that while using the focal reducer as well as the moonlite focuser I am running out of coarse focus adjustement on the SCT 9.25 Celestron.

I am only worried about this as I am considering using filter sliders, which will add more space between the scope and the focusing plane. and since I am out of coarse focus and the moonlite focuser has only 3/4 of an inch travel I might be stuck.

Any suggestions guys?

[[1ponders] (Paul)]

The solution Mark is to place the focal reducer after the moonlight focuser (I'm assuming it is a zero shift type focuser and not one that attaches to the course focuser of the scope) From memory the ideal distance from last element of the celestron FR to the imaging plane is 105mm so you will most likely need an extension tube for the DSI to achieve the 6.3 FR you are looking for. The same applies to the 3.3 FR but I don't think the distance is 105mm, it is less. Just what though I don't know.