Thread: MMOAG Issues?
View Single Post
  #1  
Old 21-09-2009, 08:23 PM
wysiwyg's Avatar
wysiwyg (Mark)
Astrophotographer

wysiwyg is offline
 
Join Date: Oct 2007
Location: Adelaide, Australia
Posts: 405
MMOAG Issues?

Hi Guys,

This is the first time I am attempting to use an OAG, so I am not sure what is normal and what to expect as far as FOV.
I have a MMOAG from Astrodon which I am using with my FSQ106N and STL camera. I have the right adapters, there is no question there.

The first time I mounted it I noticed that the stars were oval, at closer inspection I was was getting a football shape FOV as in the attachment. Hence I thought I need more prism spacers to move the prism further into the light cone.
Ordered some sapcers and fitted them but no chnage in the shape of the firld of View. I still get a football.
Is this normal, or should you be getting a nice round circlular FOV?

I manually manipulated the prism holder until I got a nice circular FOV, but the prism was in the center of the opening. This would surely obscure the mani imaging chip.
Also noticed that there is a baffle inside the FSQ, and when looking through the eyepeice holder of the OAG you can clearly see it.

Just wanting comments from people who have had experiences with OAG's and what sort of FOV do you get.
Keep in mind that with this sort of FOV I was getting oval stars using the STL remote guide head, yet using an eyepiece I was getting nice round stars.

Any comments are appreciated.

Cheers
Mark
Attached Thumbnails
Click for full-size image (MMOAG FOV.jpg)
164.4 KB73 views
Reply With Quote