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Old 17-11-2013, 05:45 PM
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gregbradley
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Join Date: Feb 2006
Location: Sydney
Posts: 18,185
Looking good Marcus. Are you putting the AO and STL 11 on there?

The MMOAG guide camera chip needs to be the same distance from the pickoff prism as the imaging camera's sensor. If you are more than about 5mm away from it the star images in the guide cam will be so out of focus they become invisible. I found this frustrating when I first tried to use my MMOAG.

Just looking at yours I would say your guide cam will be sitting in air above that helical focuser. I don't use the helical focuser as its too short plus how do you focus it when its got a guide camera sitting in it?? Spin it and tangle the cables? The designer must have been a bit soft in the head.

I substituted a Televue Barlow body and removed the lens bit on it at the bottom to get more height to fit the guide scope. My camera sensor seems a bit closer to the prism than yours. I have MMOAG then about a 12mm wide adapter then the filter wheel (20mm) then the camera and the sensor is 23mm inside the body. So that is 23+20+12+ half the thickness of the MMOAG about 10mm = 62mm.

Anyway something to be aware of when using a MMOAG for the first time.

The other thing is to make sure the adapters areall seated without any minor push out. In my first use the MMOAG prism was sticking back a bit causing the adapter to not seat 100%. I wondered why one side of the images were very soft. The prism has 2 allen key screws on top and you can slide it forward or back to suit and then retighten if its an issue.

Greg.
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