Astrodon

Hi Don, I recently purchased a MOAG ST/AO8 and have been trying to use it as a standalone unit. I have been unable to achieved focus with the guiding camera (external remote guider) once focus has been achieved on the main camera (ST2K-XCM). The manual suggests that you may have a solution for this issue. I did remove the negative lens cup as suggested in the manual. Thanks for the help...

Bob

Hi, Bob, What is the distance from the prism (centerline of the helical focuser) to the ST2k imaging detector? The focal point for the remote guide head from the prism needs to be the same distance. As shown in the manual, the distance between the prism and 0.6" above the top of the helical focuser (the image plane of the RGH) is ~ 3.5". So, if you ST2k is closer than this, you'll need to put the lens back in that will add about 10 mm of backfocus. If it is further than this, then you need to pull the RGH up and perhaps even use an eyepiece extender. Please let me know. Don