Astrophotographers hangout. Invite friends and notice chat bar on bottom.

EdgeHD/CGEM tracking

So I had a chance to try my 1100HD with the Starlight Xpress H9C. My biggest concern is that I can't seem to take a shot longer than 5 seconds, then the tracking starts to slip bad enough where the stars are oblong and blurred. I am still working on focusing, but I do know the tracking slips. For example, if I will center the M51 galaxy in Nebulosity, and after I take about 20 ten second shots, it will be just outside of the Nebulosity Frame and Focus crosshairs by the end of the shot series. This is seriously messing up my images. I have made sure to correctly balance the scope. Alignment is good, because after it drifts, I will tell it to go to M51 again, and it'll be dead centered. My only thoughts are that I need an autoguider for any shots over 10 seconds and/or the scope is too heavy for the mount and it's slipping. All I have on the mount is the scope, camera, hyperstar, feathertouch/microtouch drive focuser, dewshield, & telrad.

I usually do a 2 star alignment with Arcturus and Dubhe, then Calibrate with Vega and Antares. I need to learn how to do a Polar alignment to make this better. I bought an SXV autoguider, but its backordered so I will just have to wait and see if this fixes the problem.

0 members like this

▶ Reply to This

Replies to This Discussion

Permalink Reply by Lisa Kaminski on August 2, 2011 at 6:24pm

So, I don't know if the alignment is my problem or not. I follow the two star align procedures and can slew to any of the objects afterwards that I want, and they show up centered. They just don't stay centered for photos. I guess I am having trouble with the idea of tracking an object being directly related to the alignment procedure.

▶ Reply

Permalink Reply by Lisa Kaminski on September 22, 2011 at 7:33pm

I actually think I have a focal reducer. I will try this and see what happens. I did the polar align and it fixed the problem. I appreciate the advice!

▶ Reply

Permalink Reply by Lisa Kaminski on September 23, 2011 at 6:56am

Do you have an autoguider? If not, I would think that would help. I have not gotten advanced enough to mess with the periodic error controls. I do know that doing a scope weight balance, two star alignment and the polar alignment helped get rid of the trails at least up to 30 seconds for me. I haven't even tried anything longer than that.