[andyc (Andy)]

M83 from the Royal National Park, taken with EOS 60D, stock 55-250mm lens at 250mm, f/7.1 and ISO 1600. A stack of 4x3minute exposures, 12 minutes total, stacked in DSS, processed in Photoshop. NGC5264, a dwarf galaxy in the Centaurus A group is on the left edge.

Am learning a great deal about the iOptron Skytracker, and am pushing it and my camera as far as I think they will go (limited by periodic error of the mount and lens quality). In testing it a bit further tonight, I noticed that the periodic error was much more pronounced if the camera was positioned sideways on the mount (ie in such a way that it would be trying to rotate the mounting plate round the polar axis). Maybe this is obvious, but when I imaged objects nearer the meridian with the weight balance more up/down and not rotating the mount, the tracking errors were very much lower.

This all may explain why sometimes I can get 3 or 4 minute subs at 250mm focal length with pretty sharp stars, but then sometimes I have trailing at 100mm with <2min subs. Overall I've been really impressed with my Skytracker. Still a learning process, but it's exciting to pick out some spiral structure and details without a telescope!