Can you photograph the Moon through an off-axis guider?

Something a bit different today. Occasionally we take great photos that we didn't expect. Often this comes about when something cool happens just as we're pressing the button, and sometimes it's chance. This time it happened when inner-city Melbourne-based Paul was focusing a camera attached to an off-axis guider (OAG).

Paul uses a ZWO ASI120MM Mini guide camera on a Celestron OAG attached to a Celestron EdgeHD 1100 with Celestron 0.7X reducer. There's a mouthful!

Like the Spanish Inquisition, nobody expects a photo through an OAG... but I'll allow Paul to continue:

"I was struggling with focus on my guide camera. I had left my telescope set up after a night of failed attempts at autoguiding on Thursday night. The forecast for Friday was that it was going to cloud over, but around 8pm on Friday evening, the clouds hadn’t yet arrived and the Moon was just “there” waiting to be imaged!

"I turned the mount on and selected “Solar System Align” and selected the Moon. My polar alignment was pretty good, so the mount slewed and there was the moon roughly in the middle of my main imaging camera. I configured the parameters for the camera and shot off 1000 frames.

"Then I remembered my focus problem, so I thought - there’s a big, bright object that I cannot possibly miss - so I switched SharpCap to the guide camera and, with a bit of focus tweaking, there was the lunar surface - as bright as if it was in the main camera! I couldn’t resist, so I shot off 1000 or so frames, then repositioned slightly and shot off another 1000 frames.

"The clouds were now appearing, so I switched back to the main camera and shot another 1000 frames. By now the clouds had well and truly arrived and my night of imaging was over."

Clearly, photos taken by the main imaging camera, with its full access to the telescope's light, will be better, but the Celestron OAG's large prism provides a remarkable amount of light. More light from the OAG will give you more guide stars, and better guiding.