Posting of Questions for Bird Fair Attendees (1 Viewer)

There is a post by SIRIUS birder 11 Jan 2008 about an 1.25" adaptor on Kowa 883, which seems to be a great scope, able to handle 180x without image breakdown. I think this may work on planets.
Focal length about 500mm.
5mm TMB eyepiece 100x, suggest 6mm at 83x may be better.
The 1520g weight seems exceptional.
There is quite a lot on birdforum re astro eyepieces on Kowa and Swarovski scopes.
Also Zeiss.
The conclusions are what I expected.
Also eyepiece field lens limited to less than 20mm.
Suggests orthos may be best, which is what I use in 24.5mm fit.

Dear Binastro,

Thanks for the further thoughts on astro eyepieces on spotting scopes.

My main interest in higher magnifications is for terrestrial use, though I do enjoy occasionally using a spotting scope to take a look at the moon or a planet.

Were I to make or somehow acquire an adapter for an astro eyepiece for my Kowa , I envision switching from the 25-60x zoom to the astro ep only once in a while when viewing conditions are excellent and there is some very distant bird that I could use just a little more detail on. I think it would be very helpful to have as large a field as possible at magnifications of 80-90x or more, as birds tend to move around so much, and they so often walk, hop or fly out of even a wide angle field at 25 or 30x (or they dive underwater & come up somewhere else), and then you need to find them again.

With that in mind, this Meade 5.5mm, 82 AFOV eyepiece looked like a nice possibility:
https://www.astronomics.com/meade-5...ra-wide-angle-waterproof-eyepeice_p19567.aspx

I suppose there will be no way of knowing for sure if or how well a given eyepiece would work without actually having it in hand and holding it up to the scope.

Did see that great post by Sirius Birder a while back- that is probably what I will end up having to do, though I am not a very handy sort. I do have access to a Dremel, and it looks like it shouldn’t be too hard to follow his nice, detailed instructions for an adapter once in possession of a suitable eyepiece that seems like it’ll work. It’s interesting what you say about many 1.25” eyepiece barrels actually being slightly different sizes.

I imagine you are right about some of the manufacturers being reluctant to push their scopes to magnifications that can give more detail than 60x, but where the image doesn’t always look all that great. This is unfortunate for those of us who like to use spotting scopes to identify birds that are quite far away (which I had always thought was basically the main idea behind using a spotting scope for birding in the first place; but I am sure there would be some people who would complain about the image not looking as clean as it does at lower powers).

. Dear SEOW,
I do actually have, at least the earlier version, of the Meade ultrawide angle. I bought a set of four at what I thought was a bargain price second-hand as new. I find them to be very nice eyepieces.
However, the new price in the USA looks remarkably low, compared with the similar Nagler eyepieces, which seem to be the basis of the Meade ultrawide angle eyepieces. In the UK most things cost more than in the USA.

There is also I think the Tele Vue 3-6 mm planetary zoom eyepiece, which is good. This is unfortunately a narrow field eyepiece so would not meet your criteria. They may also have a 2-4 similar eyepiece, which is too short a focal length for your scope.

I bought the Meade ultrawide angle eyepieces, as I use fixed telescopes on astronomical objects, so I need a wide field as the objects drift through the field of view because of the Earth's rotation.

What I don't know, is whether it would work on a TSN-883 as I don't have access to this scope, although it would be very nice to have one, mainly because of the lightweight and large aperture. But it is a bit expensive.

I'm not sure if the 5.5 mm eyepiece barrel is too wide or whether it would reach focus. You would have to try it.
In theory, it is probably an ideal focal length for your spotting scope, giving perhaps 90 times magnification.
with multielement eyepieces such as these, the resolution may actually be less than a narrow angle simple design using three or four elements, or even the monocentric eyepiece, which has a tiny field of view. I have an original one which is very old.
One of my best eyepieces is the Edmunds 8mm RKE, which is only three elements, but which shows fainter stars than nearly any other eyepiece I have, even though it is only single coated. It is also very good on planets.
It is however too long a focal length for your purposes and has a 1.25 inch barrel.

Also, it is important to understand that the resolution that individuals have, depends to a large extent on their visual acuity. Some people need higher magnifications to get the optimum resolution than others who have very fine eyesight. Also of course it depends on the conditions, both during the day for terrestrial use and at night for astronomical use. Best seeing conditions at night usually occur at about 3 AM, which some people don't like. My being a night person, I don't mind this time at all.

Good luck if you find the Meade 5.5mm eyepiece works.