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ZEISS. Discover the fascinating world of birds, and win a birding trip to Columbia

Spotting scopes for use with 1.25" eyepieces? (1 Viewer)

opisska

Jan Ebr
Czech Republic
Thanks for all you advice! I was actually considering the Meopta S2 at the start of my search (since it looks like it's great and just weighed down by people's lack of trust on a small Czech company), until I found out how that the price is just for the body and how much the eyepiece costs, which started this idea of mine of using my own eyepieces - I had no idea I could do so with the Meopta itself!

Normally I would simply wait for the shop to reopen, it's just I have planned a trip with seawatching starting in 10 days and would enjoy having a new scope for that... but we'll see.
 

Tringa45

Well-known member
Europe
I was actually considering the Meopta S2 at the start of my search (since it looks like it's great and just weighed down by people's lack of trust on a small Czech company), until I found out how that the price is just for the body and how much the eyepiece costs, which started this idea of mine of using my own eyepieces - I had no idea I could do so with the Meopta itself!
Can't go wrong there. I once compared an S2 side-by-side with an 85 mm Zeiss DiaScope and regardless of price would have chosen the Meopta.
With all their contract work Meoprta is now more of an optical giant and enjoys an excellent reputation.

John
 

Binastro

Well-known member
I have the Televue 45 degree prism and I find it to be good at 100x on the Skywatcher 90mm Maksutov.

However, I appreciate that optics folks here don't like these prisms.

For my 150mm Maksutov I used a straight through Porroprism adapter, which worked well.
Or inverted view, no adapter for astro.

B.
 

Tringa45

Well-known member
Europe
For my 150mm Maksutov I used a straight through Porroprism adapter, which worked well.
I have often thought that one could assemble a superlative (if not waterproof) spotting scope using a small Borg or Takahashi fluorite refractor if a Porroprism adapter were available. Borg used to offer one and there is one available for the Kowa 500 mm telephoto lens, but with the Kowa bayonet mount.

John
 

Binastro

Well-known member
Hi John,

In my experience photographic telephoto lenses never really get up to the quality of high class refractors, and I have tested very many with eyepieces.

However, digital compact and bridge cameras easily outperform any hand held binoculars, even IS ones.

It always surprises me that the small Canon SX730 easily outresolves the much larger and heavier Canon 18x50 IS.

Regards,
B.
 

BKoh

Member
Singapore
I have often thought that one could assemble a superlative (if not waterproof) spotting scope using a small Borg or Takahashi fluorite refractor if a Porroprism adapter were available. Borg used to offer one and there is one available for the Kowa 500 mm telephoto lens, but with the Kowa bayonet mount.

John
Years ago the 70mm Televue Pronto was highly praised in a shootout against traditional spotting scopes:


It was later "dethroned" by the 65mm Pentax:


which was in turn displaced by the Televue TV-85:


Of course, this presupposes you have the budget for a Televue scope. If not, the Pentaxes are quite popular, and the Svbony SV406P seems to have acquitted itself well with those who have actually tried it (including me).
 

wllmspd

Well-known member
I use a (rather heavy) old William optics 66mm Zenithstar APO which gives very good views, even looks like a spotter in an after market cover. Something a bit bigger (and lighter) would be interesting. I see Svbony is about to release an 85mm ED Apo, no info if it can be adapted to 1.25” eyepieces. Be good to have a list of scopes that can take the APM “swaro-adapter” for 1.25”.

peter
 

Tringa45

Well-known member
Europe
Hi John,

In my experience photographic telephoto lenses never really get up to the quality of high class refractors, and I have tested very many with eyepieces.

However, digital compact and bridge cameras easily outperform any hand held binoculars, even IS ones.

It always surprises me that the small Canon SX730 easily outresolves the much larger and heavier Canon 18x50 IS.

Regards,
B.
Hi David,

The Kowa telephoto lens is more an adapted 880 scope than an ordinary camera lens. There don't appear to be any stops and there is no autofocus or image stabilisation. There is a focal reducer for 350 mm f/4 and a focal extender for 850 mm f/9,6. Magnifications with the prism unit and Kowa eyepieces are about 10% higher than with the 880 scopes, which could perhaps be explained by a negative element behind the focussing doublet.
I haven't looked through one , but some of the photographs on the Kowa stand at Photokina were outstanding.

It's difficult to compare camera lenses to scopes or binoculars. The objective diameter of the Canon SX730 would only be about 25 mm and if the objectives of the 18x50 IS were stopped down to 25 mm they would have to be pretty awful not to match it. If your eyes are good enough to cope with the small exit pupils, it's amazing what a tripler behind the eyepiece will reveal.

Regards,
John
 

Binastro

Well-known member
The tiny sensors on compact and bridge cameras are far more capable at resolution than unaided eyes.

There is also probably digital manipulation of the lens image to reduce CA and correct distortion.

Even a 2.5x Swarovski or Opticron booster shows awful quality with the Canon 18x50 IS.

The resolution provided by these 40x optical and more digital cameras equals the theoretical limit for the front diameter of the lens.

Our eyes are very poor in comparison.

Binoculars are too low magnification and too poor quality to exploit the aperture provided.

Regards,
B.

P.S.
The Canon SX 730 HS has a front lens diameter indeed of 25mm or 25.5mm.
It provides almost twice the resolution for my eyes of the Canon 18x50 IS.

However, the Canon 18x50 IS is excellent almost directly into the sun direction, whereas the SX 730 HS has very poor contrast in this direction.

P.P.S.
I will check what the actual gain is in good light, camera versus Canon 18x50 IS, although my eyesight is now not as good as it was.
 
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opisska

Jan Ebr
Czech Republic
Since my friend got better and reopened, I went to test some telescopes ... and came back with the Meopta S2 HD 82 mm. As he also sells astronomy stuff, so he had the relevant adapter as well as some of the eyepieces I actually own handy for testing, so I could see that it focuses well. Now I have tested it at home with all three relevant eyepieces (Explore Scientific 14 mm, Nagler 9 mm, Radian 6 mm) and it works very well with all of them. I had the opportunity to test it head to head against the 85-mm Swarowski and I found it hard to see any difference - I am sure the hardcore fans would, but to my layman eye, the Meopta is simply top optics. It's a bit expensive, but it's simply so good - and since I could get it to immediately take home, I yielded and bought it.
 
ZEISS. Discover the fascinating world of birds, and win a birding trip to Columbia
ZEISS. Discover the fascinating world of birds, and win a birding trip to Columbia
ZEISS. Discover the fascinating world of birds, and win a birding trip to Columbia

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