perrin6

My eyepiece case (the middle one):-

Tiredboy: Oh - just read the ETX80 has a built-in barlow so you shouldn't need to buy one just a 6mm (or thereabouts) eyepiece.

I have a 66mm quality refractor and I find X97 reasonable for jupiter although saturn could bear more magnification as it's image is a bit too small, so your ETX80 F5 (500mm focal length & has high quality optics I believe) could probably do with a 2X barlow and a 6mm eyepiece to give you 133X which should be fine for planets and double stars. X275 is WAY over the top for that aperture TBH, even if the optics were perfect, the image would be very dim and fuzzy.

My lowest power on my 13.2 inch is a 19mm panoptic which gives .73 degree actual field of view at X93. A lower power in my moderately light-polluted sky (south London) would make the eyepiece much too grey ( at X93 it is already quite unpleasantly grey). Other eyepieces; nagler X200 & 6mm X300. There is a large gap between X93 & X200 but the nag's wide field compensates somewhat I think.

X300 I need for v. close double stars and the planets. X200 doesnt quite seem enough for planetary details, in my experience, partly beacause I am near-middle aged too, I suppose. (BTW I mask aperture to 12inches for planets & double stars).

Am I missing anything by having such a large gap in the range of powers?

Alan