Problem ZWO ASI 662 and SW 150/750

I’m also very new to this but after two nights trying to photograph (video) Saturn with a Skymax 102 and ZWO ASI662MC I learned a few things that might be relevant to you.

1. At first I couldn’t not see anything with the camera using the 1.25 nosepiece directly where my eye-piece would normally go. I had Saturn in a 32mm Plossl but figured out that the camera sensor is so small that it was not even in frame. I solved this by using a 12mm eyepiece with crosshairs and placing Saturn (You could do the same with a bright star) dead center.

2. I also figured out with my f13 scope, the camera gain and exposure time had to be turned up significantly. Try something like 300 gain and 60ms exposure, your OTA is faster than mine so you might not need as much. Maybe even 200 gain will be enough but it shouldn’t hurt to crank it up to center and focus.

3. I figured out that the focus for my visual eyepieces is much different than for the camera focal plane. Once I solved the first two issues, I had light on the camera sensor but it was a big blob. I got the focus close and then a bahtinov mask to get “perfect” focus. You’ll probably need to increase expose to see anything when you add the mask.

Anyway, Hope some of this helps. I also hope you have a solid mount because you’ll want it tracking very well to keep your target in the frame. I like to watch it in the 12mm crosshairs for a bit to make sure it’s not drifting. If your target is drifting quickly across the frame it will be impossible to remove the eyepiece and get the camera mounted before you are just seeing black again.