Hi All --
I ordered an Astro Tech AT72EDII telescope today as the first piece in an AP setup. I will be using an unmodified Canon 77D on either an HEQ5 or, better yet, an EQ6 R Pro if I can wait for it to come on sale. From my reading it's clear that ultimately auto guiding is the way to go, so I want to get an appropriate auto guiding rig to go along with the above. I have a few questions:
First, "Image Scale": I calculated the image scale of my telescope/camera configuation at 1.78. What is the optimum, or best range, for an image scale for the guide camera/scope set up?
Second, I notice that a number of folks are using the Svbony 50 or 60 mm guidescopes, that look suspiciously similar to the ones that are sold by Astro-Tech and Agena, among others. Are they the same scope, because the Svbony brand is less expensive. I'm willing to pay more if the "brand" names are better, but if they are the same.....
Would the 50 mm be a good choice? I have also looked at the ZWO 30mm mini guide scope. I like this because of the small size, but I don't think you could use it as a finderscope as well. However, do I need a finderscope on the AT72, or can I just use a low power lens on its own? Recommendations?
Lastly, I am considering either the ZWO ASI 120MM mini or the ASI 290MM mini. Paired with the 50mm scope, the 190 has an image scale of 4.06, and the 290 has an image scale of 3.14. Which is the better choice, and what is the relationship between the image scale of the guide scope vs. the imaging scope?
Sorry to be so picky, but I am trying to master the details of all of this as I go, instead of just guessing.
Thanks in advance for all replies.