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Eyepieces and scopes

Started by Paultricounty, 04/27/2003 07:14PM
Posted 04/27/2003 07:14PM Opening Post
Hello Group,

I have not seen much action on this forum lately; maybe we can get it going with a few questions and thoughts.

Has anyone done any side-by-side comparison of the Zeiss .965 barrel Ortho’s and the newer Zeiss 1.25 “ Ortho’s? I know they call the newer 1.25” abbes, but I was always under the impression that the .965-barrel oculars were the true abbes.

I also am curious of users thoughts on performance on faster scopes using these oculars.

Lastly, does any body have any thoughts on the value of these Zeiss oculars changing and be coming less desirable as all the new planetary eyepieces being designed by TMB and AP and possibly TV come to market. Same question on the Zeiss scopes, will they become less valuable and desirable as the quality of newer scopes to the market place exceed these designs?

Posted 04/28/2003 10:50AM #1
Hello Paul,

I have compared the 0.96" and the 1.25" Abbe-Orthos using my Telementor and an APQ100/640
and APQ130/1000 - I must say that the 1.25" version is superior over the older Abbe's.

At first the coatings are much better. I bought my 0.96" Abbe together with the Telementor
in 1984 at the Zeiss store in (East)Berlin. The O-6 had an older MgF2 coating. So the
reflections are much higher than looking at a 1.25" Abbe. Of course - over 10 years of
optical development! But also the glasses are different in the newer Abbe's. Zeiss used some
high index lanthanum glasses and I think the internal light scatter is much lower in these

The 1.25" Abbe where designed for the new line of APQ refractors. And at these telescopes
they show high quality pictures.

I used a Pentax SMC O-6 and tryed to find differencies to an older O-6 from Zeiss and the
newer A-6. I personaly think that the Pentax and the 1.25" Abbe are closed together. I never
used a binoviewer; perhaps the pictures are different here. But again: both were better
than the older 0.96" O-6.

The name Abbe orthoscopics you gan use for any Orthos around. The design goes back to Ernst
Abbe, one of the founders of Zeiss. In honor to Ernst Abbe Zeiss put the Name "A-#" at the
barrel of the eyepiece.

The prices: I think the eyepieces sometimes are to expensive. I would not pay nearly 800 EUR
for the eyepieces or the barlow. If you can get a Pentax SMC ortho take it! The results are
equal I personaly think.

And the telescopes: I think one must see the effort Zeiss made to develop the ultimate
planet refractor when they designed the APQ. Of course you can have the same color (or
better; why not!!!) correction using high quality glasses like the FPL's and FK like for instance
Roland Christen is doing it with his top refractors (you can check in the glass catalogues
from Ohara and Schott that the optical parameters are very close to CaF2).
I think it is also some kind of beauty to use a telescope which is hand figured to give
the optimun performance for the observer; and Zeiss did it using CaF2 in a triplett.
Then you see how difficult it is to meet the high standarts of Zeiss you can imagine what high
class instrument you hold in your hands if you own an APQ. I would say the "value" is at least
equal to the top line tripletts from Astro-Physics! Again; I would not pay 11.000 USD for an
APQ130 or 7000 for an APQ100. But if you find one for the price the people are asking for their
AP refractors - take it!!! If you find one. I think people are using their APQ's as a kind
of lifetime telescope (so I am doing it).

Hopefully you do not missunderstand me - I started my astronomy "life" with Zeiss instruments.
So perhaps it is also a kind of patriotism...

Best regards from Germany,

Posted 04/28/2003 01:08PM #2
I have read Michael's reply. He seems to have had the chance to use an older 0.965 with his APQ's and to compare with the Abbe's.

Well I have yet to use a 1.25" but am delighted with my 0.965" Abbe's.

A US friend has told me is unable to tell the difference with the 10 mm 0.965 and 1.25 inch Abbe's.

Perhaps a fair test needs to be arranged.

As to the Zeiss value question, the rarity and uniqueness of the APQ's (fewer than 500 were made) means thay will long be sought after. I would suggest they will appreciate.

I know the fact Zeiss were discontinuing production in 1994/5 was a chief reason why I purchased from Zeiss an APQ 100.

It was also my first true scope and I like Michael have developed Zeiss loyalty.

Perhaps if the APQ's were re-released and more widely in circulation they would decrease in value.

I bet also if AP stopped production tomorrow the price for these scopes would appreciate with time.
Best wishes
Kevin B
Posted 05/04/2003 04:53AM #3
You have elicited replies from Michael Lalk and Kevin Barker. I'm sure I can add nothing to the wisdom they have offered. I have had the opportunity to use a Zeiss 10mm ortho in 0.965 and 1.25 size one after another in the same scope. In the seeing conditions present in the Midwest at the time I made the comparison I could not tell a difference. I am trying to acquire some additional focal lengths of the .965's and will make that comparison when I can. My thought is that for travel and public star parties the 1.25 Abbe orthos are a tad too valuable to subject to mascara and fingerprints.
I have a friend who has constructed a scope from a Zeiss achromat 130 f15. I spoke with him on the phone the other night and we hope to come up with an evening of excellent seeing and try making comparisons of the images in this scope and an APQ.
As to using the 1.25 Abbes in fast scopes--I have put them in f5 and f4.35 Newtonians and been impressed with their performance. I have not tried this with the .965 10mm that I have.
As to the new TMB and AP/Aries eyepieces making the Zeiss orthos less valuable as they come to market, we shall see. I noted in the yahoo forum for TMB that Tom Back had compared the TMB monocentric to Zeiss Abbe 1.25 and Pentax .965 and was very favorably impressed. I must say that when I "fill the gaps" between the 4,6,10,16mm Zeiss Abbe 1.25's with the Pentax .965's in 5,7,9,12, 18 that I find these oculars produce beautiful images in my scopes as well.
I suppose one goal is to be in the happy circumstance that each time you observe the quality of the image is determined by the seeing conditions that exist, not by a rate limiting piece of your optical train (scope,diagonal, or ocular.) I think that with any of these orthos in AP, Zeiss, Tak refractors or Newtonians with Zambuto or Swayze mirrors (and others) that one has probably achieved that goal.
Bring on Mars. The party is at Kevin's place.