Bino Viewer Problems

[HRT]

Greetings,

I have an older style Celestron/Baader binoviewer to which are fitted matched 26mm EPs.

However, the system will not come to focus on my f7.5 952mm FL refractor, as there is not enough inward focus. Similarly, the viewer will not come to focus with EPs of longer or shorter FLs.

If you have a solution I would very much like to hear it.

Cheers and best,

HRT

[Barrykgerdes]

This is a common trouble with bino viewers and without the long focal range that some SCT's have there is no easy solution without moving the primary mirror.

However there is a way that will work with some viewers.
A Barlow of the Meade/Celestron type has its lens detatchable at the bottom end of the tube. The thread is the same as a filter that can be screwed into bottom of most plossl eyepieces.

If you can use this lens screwed into the bottom of the bino viewer it will move the focal point out to a position that may allow the assembly to come into focus. I have used this method on a number of scopes with insufficent focus range to support diagonals etc and other objects added to the focus tube.

Using this method of course will halve the FOV due to the barlow magnification.

Barry

[HRT]

Much obliged Barry. I think I will end up selling them unless I can get them to work in my SCT.

Cheers,

Hedley

[Saturnine]

[
Hi HRT

Another possibility to try, if you are using an 2" diagonal, try swapping it for an 1.25" diagonal, that should give you an extra 30 / 40 mm of.
infocus travel. May still not be enough but worth a try.

Jeff


QUOTE=HRT;812217]Greetings,

I have an older style Celestron/Baader binoviewer to which are fitted matched 26mm EPs.

However, the system will not come to focus on my f7.5 952mm FL refractor, as there is not enough inward focus. Similarly, the viewer will not come to focus with EPs of longer or shorter FLs.

If you have a solution I would very much like to hear it.

Cheers and best,

HRT[/QUOTE]

[dannat]

The 1.25" diagonal will help buy you need an optical corrector or OCA

The moving mirror of a SCT does not require ones they just about all can move far enough o focus, but newts/refractors just about all require one

You old just hack 5cm off the refractory tube :D