if you don't have a good focuser don't get a oag! its just suicide so to speak. Im not completely sure on the oags on the market i cracked the wobbles because they wanted 1300 for a 3" varient which i wasn't and couldn't pay so i built my own see
here and
here and
here and the results of it
here that last one has a animation for oag and non oag guided and well pretty much explains why! My oag isn't refined like the MMOAG and the like but its very effective!
I have seen the TS 2.5" varient the weekend just gone past and it works. the only other thing you need is a sensitive guide camera or you will pull your hair out what do i mean by that. something in the Loadstar or Sbig 402 catagory its fine when your in a dense star field but if you get into some open space you will struggle to find stars. sometimes i get the sbig into bin 3x3 and even 4x4 territory and thats 36 micron pixels with 90% QE which basically means its really dull and im guiding on a square
but it works!
Good luck and ask questions if you need more help
