82 eyepiece 1.25

[alro]

Hello again,

another ep question.

thanks for all help and advice so far, so at 82 degree fov what is the longest fl at 1.25. i think my preference would be longer fl to begin with to see how i get on, i can always use x2 barlow with it.

Al

[michael.h.f.wilkinson]

The longest I can think of are the 16mm T5 Nagler and 18mm MaxVision. Curiously, the 17mm T4 is 2", but that may be because of the extra glass needed to get the longer eye relief

[John]

The longest 82 I've seen regularly is the 1.25" fitting is the Meade 5000 18mm UWA. I did have a 20mm 84 degree KK Widescan III eyepiece once that was in the 1.25" fitting. It was great at F/8 and slower but the edges of the view suffered in faster scopes. The Widescan III's are rarely seen unfortunately.

[damnut]

hi ALR,

Covered really above with the 82 deg afov in the 1.25" format. The restrictions on the field stop and constraints on your field of view come in to play once you start using the longer focal length 1.25" e'ps. There is a 55mm ep but this generates an afov of 30 degrees roughly, due to the restrictions of the 1.25" barrel.

Have a play here :--- http://www.stargazing.net/naa/scopemath.htm

[SpaceWalker]

Yes, at 82*AFOV your 1.25" choice is limited to the 18mm Meade 5K UWA (second-hand only) or 18mm Maxvision. Another option could be the 24mm 68*AFOV Maxvision or ES68.  To avoid vignetting you'll need for any of them either 1.25" telecentric extender or 2" telenegative Barlow.