PST & Diagonal

[imarcs]

Is it feasible to use a diagonal with a PST?

I'd like to mount mine onto my skywatcher Alt/Az mount.

Ive got a spare dovetail plate, and a plan to weld a baseplate onto it but i cant do that till next week - and i want to play today. So the best i can do at the moment rotates the PST by 90 degrees

I have very little knowledge of how optics work so this may of course be a ridiculous question. Any advice gratefully taken.

[Photosbykev]

Fitting a diagonal to a PST wouldn't work, you will never achieve focus with the combination

[Merlin66]

The penta-prism inside the black box limits the position of the external focus.

It could be possible to remove the penta-prism and replace it with a front surface mirror. You then have to remove the eyepiece holder and fit a small focuser (helical?) and spacers to get back to the focus position.....

IMHO it's not worth it!

It would be just as easy dumping the black box and fitting spacers/ focuser/ diagonal similar to the Stage 2 PST Mod.

(PST Mod write-up available (6Mb) -just PM an email address for a copy)

[imarcs]

Yeah i thought i might be off the mark. Thanks for the info guys.

I've managed to get it the right way up using a heavy duty binocular mounting bracket. But now of course its raining!!!!

Merlin - i would be interested in your Mod write up. I'll PM you my email address - Thanks.