Hi guys -
I replaced my ST80 guidescope with a shorter, faster one from Teleskop Express - this one: https://www.teleskop....php/info/p6383
It arrived today and I fitted it with my ASI120MM and was disappointed to find that I just can't get sharp stars with it. They are misshapen and assymetrical. Here's a link to a short video I took showing my focus procedure - I'm sliding the focus barrel in and out during the video by tiny amounts at a time, passing through the point of best focus to the other side and back again. You can see the point of best focus just isn't good at all.
I know guidescopes don't tend to be great in terms of image quality, but this seems excessive?