[pluto (Hugh)]

Last night I finally had an opportunity to try out my new STT-8300M with my newish Tak TSA120.

Before setting up for imaging I had a look at the moon and Jupiter through the Tak and the views were awesome, super sharp and great colour.

But when I started imaging I noticed my stars were coming out triangular.
There was probably some flex in the focuser and the extension tubes as the backfocus is huge on this scope.

Reading around the net it sounds like it could be a collimation issue or pinched optics, both of which I'm assuming are hard/expensive to fix with a Tak..?

This image is a 1:1 crop from just off the centre of a 10min Ha exposure. Guiding looked pretty stable and focus was spot on according to my bahtinov mask. The stars are a pretty uniform shape accross the whole image too.

Any advice would be greatly appreciated!