The 8" or 10" Newt will both exceed the carrying capacity on the EQ5. The 8" might be alright for visual if well balanced but for imaging, forget it.
The 127mm ( 5") Mak will sit on the EQ5 quite happily but from what I've heard the ED80 will do a better job. With a Barlow you'll get a bigger image but you will be definitely stepping into the guiding world to acheive good imaging. Planetary imaging will work ok without guiding of course but DSO's is another matter altogether.
I'll be interested to see how your guiding project will work.
|