Spotting scopes for use with 1.25" eyepieces? (2 Viewers)

[opisska]

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]

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]

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]

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]

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]

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:

Scope Fever! | Better View Desired

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

Pentax 65 mm Spotting Scope | Better View Desired

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

Tele Vue-85 600mm f/7 Spotting Scope by Tim Gallagher and Kevin McGowan

Tele Vue Optics, founded in 1977, has been thrilling amateur astronomers since 1979. It is our mission. It's in the materials we choose, the designs we create, the craftsmanship we demonstrate...the images we deliver. Creating <i>goodies</i>for the observing enthusiast has been founder Al...

www.televue.com

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]

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]

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]

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.

 

[opisska]

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.

 

[Binastro]

Well done, and pleased that your friend is better.

I hope you have much enjoyment with the new scope.

Best wishes,
B.

 

[opisska]

Coming back to conclude that this was a fantastic idea. Getting the Meopta has completely transformed my birding. I used to bring out the scope only when there was no other way and even that was sometimes hesitant. Now I started just looking through it for the joy of it. It's for two reasons - the view is so attractive and immersive (especially with the wide angle astro eyepieces) and it's just so practical - it's much lighter than any of my old scopes, it's 45 degrees, it focuses easily, doesn't fall apart. To be honest, a big part of this is the Manfrotto tripod, which I got three years ago - with the old wonky Velbons I had it wouldn't have been nearly as good - but the Meopta is the key.

Am I sad I didn't get a "proper spotter" earlier? Not really. I looked through some of the "affordable" scopes and the views were nowhere near that great and the general experience wasn't that different from my cheap Maks. And I would not have gotten a Meopta two years ago, no way at that price and my income.

I used to advertise the Maks as the solution and I used to advice birders to not get caught up in the craze for "top scopes" and don't throw insane amounts of money on a scope. I am changing my recommendation: if money is tight, my previous advice holds. If 1500 EUR isn't a big deal for you, then by all means get a spotter from this class (I assume that other similar products mentioned here in this price range are comparable to the Meopta), there is a big chance you'd enjoy it.

I will still laugh at the prices of the Swarowskis though, that's just insane and pointless.

 

[jring]

Hi Jan,

great to hear you got a nice new scope - and even better to hear that your friend is well again...

Enjoy the view!

Joachim

 

[Swedpat]

Since long time I have thought it's a pity that the most spottingscopes cannot use 1,25 inch eyepieces. That would increase the options to eyepieces to hundreds.
Therefore I became very happy that Pentax's spottingscopes are made for astronomical eyepieces. I now have both the straight and angled version of the 65mm model.
A while ago I got to know about another spottingscope: Delta ED Titanium. It's claimed to be the worlds most compact 50mm spottingscope. I mainly use it with Baader Morpheus 12,5mm, which gives 13,6x.
Excellent little scope except from for photography. There is a pretty significant amount of pincusion distortion due to the short focal ratio of f/3,4. That is not close to noticeable visually as on a photo, though.

 

[Swedpat]

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

Scope Fever! | Better View Desired

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

Pentax 65 mm Spotting Scope | Better View Desired

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

Tele Vue-85 600mm f/7 Spotting Scope by Tim Gallagher and Kevin McGowan

Tele Vue Optics, founded in 1977, has been thrilling amateur astronomers since 1979. It is our mission. It's in the materials we choose, the designs we create, the craftsmanship we demonstrate...the images we deliver. Creating <i>goodies</i>for the observing enthusiast has been founder Al...

www.televue.com

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).

I just read the review at Cloudy nights and it surprises me. While the 65mm Pentax is a good instrument I don't find it THAT good. I have tried it with different high quality eyepieces but don't find it worth to go much higher than 30x. It's practically without CA even at 78x but the image is not sharp at all using Vixen LV 5mm eyepiece. I also tried with Baader Morpheus 9mm(43x) and Televue Delos 10mm(39x). I did not find it worth to use these eyepieces compared to Baader Morpheus 12,5mm which gives 31x.
How can Pentax own eyepieces provide a "extremely sharp, high-contrast image" and that with 58x, when Televue does not do it at 39x?
Televue is considered to be the one of the alpha eyepieces out there, along with Pentax own models. And some mean Baader Morpheus is as good as Televue Delos. Is it that Pentax eyepieces are so specialised to be compatible to their own spottingscopes(or the other way around), that no other brand works close to as good? Is that even optically possible?
IF that is the case and I can get an excellent sharpness with Pentax eyepiece at 58x, this would just be awesome!
Or are later Pentax 65mm spottingscopes not as good as the earlier?

 

[BoldenEagle]

It may well be that your particular Pentax sample is not so great. Have you star tested it or compared to other samples? If the scope has bad aberrations, switching the eyepiece is not going to help.

Regards, Juhani

 

[Swedpat]

It may well be that your particular Pentax sample is not so great. Have you star tested it or compared to other samples? If the scope has bad aberrations, switching the eyepiece is not going to help.

Regards, Juhani

If I recall right I got the same result with the straight 65mm as well(I have both). So I draw the conclusion Pentax lowered the optical quality at some moment with this spottingscope.
I will do another comparison between the two tubes.

Regards, Patric

 

[henry link]

I agree with Juhani. Since the true quality of both scopes is unknown at this point, both need to be star-tested rather than just visually compared to each other. That's the only way to determine exactly which aberrations or defects are causing the poor performance. Judging from your description spherical aberration is the most likely culprit, but it could also be astigmatism, coma, a defective roof prism edge or a combination of all of those. Star-testing is the only sure way to find out.