TheSkySearchers

My eyepiece collection ranges from about 10° up to 84° but my favourites are in the 30° to 45° range followed by 50° to 60°.
I enjoy planetary, lunar and double stars mostly but do view pretty much any object within reach of my telescopes.
I do like viewing DSOs but I am not much for 'framing' a object with a over large FOV, and any eyepiece that I have to turn my head to find the field stop will probably become a paperweight quite quickly.

My preferred AFOV is similar to yours, but more like 40-50 degree eyepieces.Then there are the 60-70 degree AFOVs which are second place. My observing is more tilted towards DSOs than planetary and double stars. I will go for framing a DSO since the wider AFOV can frame an object at smaller exit pupil than otherwise.

I value being able to use the eyepiece in the daytime and have straight lines be straight. So the field distortion in the 80 and 100 degree AFOV oculars is pretty annoying. For a long time I though that it was a crime against optics that I loathed the 80 degree formats so much. Bought a set of Naglers sold it and made the mistake of trying them again to sell them again. I also used to have 3 100 degree format oculars that were simply toys.

One thing I noticed in my samplings of the really wide fields that ALSO annoyed me was that it seemed that there were quality control issues with the coatings. One of the last t6 Naglers and all the 100 degree AFOVs had a variable sky background. It looked dirty. I examined closely and it seemed to me that there were slight variations in the coatings.

For the wide field framing, when I want to do that exercise, I'm happy with the 60-70s. The 80s and 100s are gone. They were too much "IT'S ALL ABOUT ME!".

I have a preferred range from 72° to 76°. That's what my Delos and Morpheus eyepieces show. These are high image quality, low angular magnifications distortion eyepieces, but it is not just that.

For panning the Moon or the Milky Way with pleasure 60° or lower is less suited as I want to know I came from and where I'll turn to. The subjective disadvantage of 82° and up is that I cannot see the whole field at a glance which makes taking in the entire field feel like an effort.

I like my 82's. Working with an dobson without any tracking it's nice to see the object for a while without nudging the telescope. No experience with 100,s but turning your head in order to see an object doesnt appeal to me.

I like eyepieces with a 68 or 70 degree AFOV. That is quite wide enough to get a good, broad view, without giving you a "marooned in a space suit" feel.

For DSOs I have tried 40 to 82 and gravitated to ~70 at the end. For planets, Moon and doubles I prefer 50 to 60. Bellow 50 feels too narrow for me.

Bigzmey wrote: ↑Mon May 24, 2021 4:25 pm For DSOs I have tried 40 to 82 and gravitated to ~70 at the end. For planets, Moon and doubles I prefer 50 to 60. Bellow 50 feels too narrow for me.

You should try a ball lens, on axis about 5-15° AFOV on axis, everything outside that is blurred but you will have the cleanest most contrasty view in center. Quite amazing views.
ER is usually 5mm and less though.

KathyNS wrote: ↑Mon May 24, 2021 11:49 am I like eyepieces with a 68 or 70 degree AFOV. That is quite wide enough to get a good, broad view, without giving you a "marooned in a space suit" feel.

I had a set of Nikon NAV-HW (102°) on loan for a while, the views were spectacular but I just did not enjoy that I had to keep turning my head to see the entire FOV.

Lady Fraktor wrote: ↑Mon May 24, 2021 4:32 pm

Bigzmey wrote: ↑Mon May 24, 2021 4:25 pm For DSOs I have tried 40 to 82 and gravitated to ~70 at the end. For planets, Moon and doubles I prefer 50 to 60. Bellow 50 feels too narrow for me.

You should try a ball lens, on axis about 5-15° AFOV on axis, everything outside that is blurred but you will have the cleanest most contrasty view in center. Quite amazing views.
ER is usually 5mm and less though.

Do you means the Herschel eyepiece? Not the monocentric.....

Lady Fraktor wrote: ↑Mon May 24, 2021 4:32 pm

Bigzmey wrote: ↑Mon May 24, 2021 4:25 pm For DSOs I have tried 40 to 82 and gravitated to ~70 at the end. For planets, Moon and doubles I prefer 50 to 60. Bellow 50 feels too narrow for me.

You should try a ball lens, on axis about 5-15° AFOV on axis, everything outside that is blurred but you will have the cleanest most contrasty view in center. Quite amazing views.
ER is usually 5mm and less though.

No, thank you. For me blurry edges are worse than narrow field.

I have 1 Herschel style but a few others that are ball lenses.
There are a few places still to buy them I think and there are many places to buy the components to make them yourself.

Bigzmey wrote: ↑Mon May 24, 2021 4:45 pm No, thank you. For me blurry edges are worse than narrow field.

These would be perfect as you can have both!

Lady Fraktor wrote: ↑Mon May 24, 2021 4:52 pm I have 1 Herschel style but a few others that are ball lenses.
There are a few places still to buy them I think and there are many places to buy the components to make them yourself.

I'm curious, now....

I just checked and Sieberts still sells his Planeshere eyepieces and Edmunds still sells components to make them yourself.
https://www.siebertoptics.com/Planesphere.html

Lady Fraktor wrote: ↑Mon May 24, 2021 5:18 pm I just checked and Sieberts still sells his Planeshere eyepieces and Edmunds still sells components to make them yourself.
https://www.siebertoptics.com/Planesphere.html

I found the lenses on the Edmund Optics site. https://www.edmundoptics.com/f/used-ili ... ses/14111/

The material is fused silica so better transmission in the UV, likely an advantage on DSOs.

Still.... looks pretty Herschellian to me.

Fused Silica and BK7 are the most common though Steve Coutre and Sieberts made sapphire and ruby ones for a while.
I suppose it is just interpretation, a Herschellian to me is a ball with a flat not completely spherical.

Lady Fraktor wrote: ↑Mon May 24, 2021 6:40 pm Fused Silica and BK7 are the most common though Steve Coutre and Sieberts made sapphire and ruby ones for a while.
I suppose it is just interpretation, a Herschellian to me is a ball with a flat not completely spherical.

Yes on interpretation. For me Herschellian is a sphere with a spherical cap removed, the thickness of the cap can vary from zero to the radius of the sphere.

Mine is 76° & less, apart from ES92s which are exceptionally usable for UWA. Most important though is effective eye relief, as I need to wear glasses.

As wide as physically possible.
Below a 9mm focal length I can observe without glasses, so 100-110°.
Above 9mm, I'm limited to 76-85° because of the use of glasses unless I want to use eyepieces well over a kilogram apiece like the ES 92s.
It's OK, though. I don't fee deprived to use eyepieces that narrow, though I do miss my 100° eyepieces in 10-21mm focal lengths.

The md-optics in Berlin Wandlitz has as a rule an assortment of the optical glass spheres (BK7) with the quality certified by a manufacturer.
Now, someone has purchased nearly everything, just this 2.4mm size left, 99 pieces available,

https://www.ebay.de/itm/265072397869?ha ... Sw1ZBUrpsa

Best,
JG