What makes an eye piece great?

[astro744]

Originally Posted by Miaplacidus

It has Televue Panoptic 24 written on the side.

I concur. The Tele Vue 24mm Panoptic eyepiece is the most versatile eyepiece Tele Vue has ever produced and gives remarkable views in any telescope.

It has the largest field stop available in a 31.7mm (1.25" barrel). (I know there was an eyepiece with 27.5mm available at some stage but I'm not sure how 'good' it was).

The maximum field stop diameter gives the following true fields and exit pupils:

0.76 deg in 2000mm, f10 SCT, exit pupil = 2.4mm.

1 deg in 1500mm, f5 Newt., exit pupil = 4.8mm.

1.7 deg in 900mm 'scope.

2.5 deg in 600mm, f7.5 ED80 refractor, exit pupil = 3.2mm.

4.3 deg in 360mm, f6 refractor, exit pupil = 4mm.

The 68 deg apparent field is just about perfect as you do not have to move your eye around.

The 15mm eye relief too is just about perfect for non eye glass wearers (not tried it with glasses).

The 1.25" barrel means it fits more telescopes and also uses less expensive 1.25" filters.

Combine with a 2.5x & 5x Powermate and you get a 9.6mm and 4.8mm wonderful planetrary eyepiece. The Powermate is needed to keep the eye relief at 15mm and avoid blackouts.

In fact if you want a minimalist eyepiece set the the 24mm Panoptic, 2.5x & 5x Powermates are ideal. You can add a 19mm Panoptic and/or 16mm Nagler later to the mix and you wont need anything else in 1.25".

[Miaplacidus (Brian)]

This is how you know if an eyepiece is great: it's common, but you seldom see it come up for resale in IIS classifieds.

[AG Hybrid (Adrian)]

What about an eyepiece over 40 years old but still coveted by astronomers today? I.E. The Edmund 28mm RKE. I received mine recently and its shot straight to the top of the list of most enjoyable eyepiece I have ever used. I use it in an F5 scope as well. Truly something special about that little eyepiece.

YMMV however.

[Varangian (John)]

The happiness it provides the observer.

[expon (Jas)]

It seems people here end up gravitating towards higher end eyepieces. Im curious as to the sizes of the pieces that make a good set.

[Renato1 (Renato)]

Interesting question, which for me has no one answer. For me, I have "great" eyepieces in particular telescopes, though looked at in general, most people would laugh at my choices which I arrived at by trial and error.

For example, in my C8 SCT, my favourite eyepiece is still a no-name brand 20mm Erfle I bought from Pocono Mountain Optics decades ago. Yes, there were better wide angle eyepieces around even back then, but finding very faint galaxies and planetary nebulas always seemed effortless with this eyepiece.

I have a relatively small, ultra wide angle 16mm Widescan eyepiece whose performance varies from sub average to abysmal in all bar one of my telescopes. But in my 80mm ED f/6.3 refractor, it is magnificent for general viewing.

In my 14.5" dob - an old style big 9mm Nagler does all the work, and is plainly great in that dob. But I've hardly used it in other telescopes.

In my first telescope from 3 decades ago, a K-mart Focal 4.5" reflector, I stll get eyepopping images from a .965" 25mm Meade Modified Achromat eyepiece (unfortunately, images from the same eyepiece in 1.25" size, don't really cut it in other telescopes).

But I do have one eyepiece which I've consistently used across nearly all my telescopes over the years, and is still the one I reach for when I want highish power - and that's my old 5 element, 6.4mm Meade Superplossl. I've got more expensive long eyerelief eyepieces in the same range, and more expensive Meade high power Ultrawides, and orthoscopics, but despite its narrow eyerelief, I like that 6.4mm Meade best - it has a huge sweet spot.

Regards,
Renato

[rrussell1962]

Having owned quite a few different telescopes and eyepieces over the past 40 or so years, I still think Orthoscopics take some beating for planets and double stars. My first telescope was a 60mm refractor and putting an Orthoscopic in to replace the MA's that came with it gave me one of my biggest equipment wow moments.