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Eyepiece 1.25" Wide angle? (1 Viewer)

Granpoli

Well-known member
Spain
Hello,
Is there any spotting scope that accepts 1.25" astronomical eyepieces..and in particular any wide angle 72° or 80° eyepiece that does not present vignetting?
Thank you
Gpoli.

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Hi,

off the top of my head, Pentax and Celestron without adapters. Probably forgot some lesser known brands.
If the eyepiece mount is wide enough, adapters are possible. Kowa big body line and Zeiss Diascope come to mind.

In general, the main question for all adaptions is whether the eyepiece will come to infinity focus (or at least far enough for birdwatching if astro is not of interest).

As for wide angle EPs, the usual criterion is 60 deg apparent field of view or more. Only the long focal length and thus low magnification ones might vignette due to prism size. You can use a short focal length Nagler or Ethos in a spotter just fine w/o vigneting... if they come to infinity focus in your instrument.

Joachim
 
I currently have a Kowa 883 which will take an adapter for 1.25-inch eyepieces. I previously had a Meopta Meostar S2 that also took an adapter for Astro eyepieces. In both cases I used a variety of eyepieces, including Pentax XWs, Morpheus, and others without any issue of vignetting or failing to reach focus.
 
Hi,

off the top of my head, Pentax and Celestron without adapters. Probably forgot some lesser known brands.
If the eyepiece mount is wide enough, adapters are possible. Kowa big body line and Zeiss Diascope come to mind.

In general, the main question for all adaptions is whether the eyepiece will come to infinity focus (or at least far enough for birdwatching if astro is not of interest).

As for wide angle EPs, the usual criterion is 60 deg apparent field of view or more. Only the long focal length and thus low magnification ones might vignette due to prism size. You can use a short focal length Nagler or Ethos in a spotter just fine w/o vigneting... if they come to infinity focus in your instrument.

Joachim

Good point. I have tried scopes such as the Celestron Regal, Olivon T650/800 , Acuter DS Pro that in theory accept all 1.25" eyepieces. But will not get infinity focus with UWA eyepieces such as the Celestron Axiom and Skywatcher Nirvanna ES-82
 
Vignetting depends on the FOV and not the AFOV: - spotting scopes that accept and reach focus astro 1.25" eps can use 110º eps!
The FOV limitation depend of brands and, eventually, models.
From what I read, there are some Chinese made spotting scopes that have reduced aperture prisms that will vignette with wider FOV eps.
Optolyth 100 and Pentax PF100 and Opticron ES100 scopes have prisms wider that the maximum 1.25" FOV.
Other Pentax scopes have FOV at least similar to the XW20. Will reach focus with all eyepieces that need less infocus than Pentax eyepieces.
Some producers instead of FOV use Field-stop values.
Some producers indicate focus position values or at least classes of focus, as TeleVue.
 
Astro adapters are available for some spotting scopes with a bayonet fitting.
I have them for my Kowa 883 and my Swarovski ATM (currently ATS). The Swarovski adapter may be hard to find but the 1,25" Zeiss Gavia adapter should be compatible with the Swarovski bayonet.
I have not had any problems reaching infinity focus with the Swarovski but the Kowa is less tolerant of some eyepieces. However, many Televue 1,25" eyepieces are almost parfocal and Plössls, Panoptic (19 mm, the 24 mm would vignette) and 82° Type 6 Naglers all work with the Kowa, so should work with anything. The only downside is the current price of Televue eyepieces.

John

PS:- Congratulations on reaching the semifinal. I have to admit that you were marginally the better side even though the ref denied us a justified penalty! :(
 
APM sell a swaro 1.25” bayonet adapter, very little info on using wide angle eyepieces with it.

Peter
I couldn't find anything on the APM site but bought one of these Swarovski Astroadapter many years ago. They only had a limited number made, patterned on the original adapter when Swarovski offered a rebadged 6 mm Vixen LV for 77x on the AT80/ST80.
Wide angle as such is not a problem, just the ability to reach infinity focus. Nagler Type 6 should work with anything but are crazy expensive.

John
 
... Type6 naglers are good, cheaper than Ethos! ...
Yes, but Ethos are on other league!!! Besides having much wider AFOVs, Ethos are also much more comfortable to use. The 5mm 1.25" Ethos clones need less infocus than TV so reach focus on more spotting scopes... (y) If money is no problem and 1.25" Ethos reach focus, I would go for the Ethos - these are the originals, not the copies... Unfortunately Ethos don't have eye-relief enough for most eye-glass users like me...:cry:
 
Stop giving me thoughts to get a XWA 13mm! (13mm being my general working eyepiece for moderate magnification - I have a 5mm Nagler for high power.
I fear I might fall into the eyepiece with a 110def field - if I could see all of it in one go, I have found I can’t see the field stop with some very wide eyepieces.

Peter
 
I fear I might fall into the eyepiece with a 110def field - if I could see all of it in one go, I have found I can’t see the field stop with some very wide eyepieces.
I remember an old publication by Zeiss about very wide eyepieces. They found that anything over 90 degrees made most observers very uncomfortable in terrestrial viewing.

Hermann
 
I hate the 100 degree Ethos.

I cancelled my pre order for a 110 degree Ethos.

I am very happy with 82 degree eyepieces and one 92 degree eyepiece I have.

Regards,
B.
 
Stop giving me thoughts to get a XWA 13mm! (13mm being my general working eyepiece for moderate magnification - I have a 5mm Nagler for high power.
I fear I might fall into the eyepiece with a 110def field - if I could see all of it in one go, I have found I can’t see the field stop with some very wide eyepieces.

Peter
Don't test a 100º AFOV ep if you don't want to buy one... ;)
I tested an Ethos and had to get an Ethos 17... Than, other 92º, 102º and 110º "came" to me...:whistle:
 
I remember an old publication by Zeiss about very wide eyepieces. They found that anything over 90 degrees made most observers very uncomfortable in terrestrial viewing.

Hermann
It depends on the observer and the eyepiece...
Since I use eye-glasses, nowadays I prefer the ES92 eps, but give me a >100º eps with good eye-relief and I will prefer it...;)
 
Don't test a 100º AFOV ep if you don't want to buy one... ;)
I tested an Ethos and had to get an Ethos 17... Than, other 92º, 102º and 110º "came" to me...:whistle:
Hi David,

I assume that most 100 deg EPs are used in your TMB as they're 2"? Or did you find a way to make them work ok on spotters with your adaptions?

Joachim, who got a cheap ES 100 deg 9mm and the space window effect is nice... but truth be told the useful field is not a lot larger than a Nagler unless doing funny eye movements...
 

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