Guide scope diagonal

[Contraindicated]

Hi,
I’m just starting out and have decided to add a guide scope (larger than the small scope that comes with it) and I tried to add a diagonal 1.25 with the intention of making it easier to view targets.
Unfortunately, I cannot get the scope to focus with the diagonal. The scope will focus without it, with the same 40mm eyepiece.
Is there a way to fix this issue? Or, do I need a different diagonal?

[Dave882]

Hi there
Most finderscopes have a fixed focus so you can’t really adjust them to incorporate extra length to the image train (back focus). When you add a diagonal to the light path you are going past the focal point so you won’t be able to focus. As an alternative you can get a finderscope with a diagonal that’s built into the scope. Like this:

https://www.ozscopes.com.au/skywatcher-9x50-right-angled-erecting-finder-scope.html

Hope that helps.

[Contraindicated]

Thanks Dave

[Dave882]

Some find using an illuminated sight like a telrad easier than a finderscope. Personally I use a starsense camera with my celestron cpc800 so haven’t used a finderscope for quite a while!

[Contraindicated]

The starsense looks interesting! Would it work in the Southern Hemisphere?
It looks like it makes the alignment more successful and increases the mounts accuracy.
Would you say it’s worth the price?