Focus issue

[rumples riot]

Now I need some help here. I have a 10 Lx200 as most of you know. On the back of that I put on a focal reducer first, then the field derotator, then the zero image focusor, then the off axis guider and finally the camera. With the focal reducer in place I cannot obtain focus. Now I know I have got a long focal train happening here, but Meade has implied that this should not be a problem.

I had wanted to use the focal reducer to get a wider field and speed up my shots and still use the field derotator to counteract field rotation. as Gary has suggested I could take short shots and not use the field derotator. But that would mean wasting $800.00.

Now if my scope has a focal length of 2500mm, and the tube is 500mm long why can't I gain focus? Can anyone help me work the numbers on this? All theories and comments considered.

Paul

[Mick]

Paul, is it possible to move the mirror in or out of focus more with the original focuser, relock the mirror and then refocus with Zero image focuser at the new mirror position?

[rumples riot]

They are ringing Meade to see what the problem is. Might try turning of the focus knob back, I don't think it will work, but you just never know. Thanks Guys for the advice, always worth another mind giving some imput and another angle to the problem.

Paul:)

[gbeal]

Paul
I agree with Mick, try the "original" focus knob as this will affect the focus point, over and above the zero image shift focuser.
I have the same sort of setup on my Mewlon. I didn't like the slight image shift, so fitted a Moonlite dual speed to the rear thread. Now I can coarse focus with the "knob", and fine tune with the Moonlite. With large changes, like the bino viewer it is a definite plus.
Why waste the $800, couldn't you sell it?
Let us know if any of this works,
Gary

[rumples riot]

thanks guys, I will give the focus knob suggestion a try. Just never know what can happen. I will get back to you when I have tried.

Paul