OAG with GP camera

[bhenderson50]

as a new user, I am finding that the star images on my GP guide camera are badly distorted, as in elliptical. Is this an issue with the position of the pick-off prism, or something else?
Thanks for any help,
Bob

[vince]

Hello Bob,

When using an OAG the shape of the stars can be deformed by a few things, the most common being the area of the telescope objective where the OAG prism is pointing, moving the prism towards the centre will help. Being slightly out of focus can also cause the stars to deform on the screen.

I hope this helps.

Best regards
Vince

[bhenderson50]

thanks for the help Vince, I will give this a try next time I have a clear sky.
I don't suppose you can help with that, can you?

Bob