Hi- I have a question about a 700mm , 60mm reflector telescope. When I use the eyepiece in the scope all is fine. When I install the 90 degree mirror I cannot bring an image into focus. It seems that there is not enough travel on the rack/pinion. The telescope did not originally come with the mirror. When I use the mirror with the 2x barlow, it works fine.
Also when I look above the mirror without the eyepiece installed, I can see the image at some distance away, but not when I move closer to the mirror.
By installing the mirror, do I change the focal point?
Can I machine an extension tube to place between the mirror and the eyepiece? If so, at what length?
After reading soem of the post,is it possible that the mirror is defective?

As you can probably tell, I am new to telescopes, so please pardon my ignorance.

Any help would be greatly appreciated.

• Focus problems. - bobmay - September 16, 2001 - 19:51 UTC