What is the best type of diagonal to use for a Maksutov Telescope?

[sojourneyer]

Should it be a mirror diagonal or a prism diagonal and why?

Ditto for a refractor.

Thanks

[Don Pensack]

In a Maksutov, the long f/ratio means either a prism or mirror can be used.

Pay attention to clear aperture diameter if using long focal length eyepieces with large field stops.

 

In the refractor, it depends on the scope.

If the scope is a triplet, or a doublet longer than f/12 (at 4") or f/9 (at 3") or f/18 (at 6"), then either type of diagonal.

If the doublet is shorter than that, and the scope is not a triplet, then I'd use a mirror.  You don't want to add any CA to what the scope already has.

Edited September 30, 2023 by Don Pensack

[sojourneyer]

thanks for the sage advice Don.  Much appreciated.