Long time ago, APM-Telescopes and TMB-Optical ( Thomas M. Back ) discovered , that this Carl Zeiss West-Germany made microscope-eyepieces beeing manufactured in a quality which can more then compete with the world-famous astro-eyepieces from Zeiss and Pentax. This Carl Zeiss eyepieces , accept the W25x10 foc. ( f=10 mm ) , offering a high eye relief , which allows you to wear eye-glases during observing. All eyepieces are applied with the most modern and famous Zeiss T* MC-coating and all air-to-glas-surfaces with a transmission-grade such high, then not many astro-eyepieces can hold up. The view through the eyepieces offers you a pur-white image with a sharpenss and contrast of such high quality , that even the best astro-eyepieces cannot top that anymore.
In normal telescopes, Refractors, Schmidt Cassegrain, Maksutov Cassegrain the eyepieces show a almost to the edge sharp image. Only in fast refractors and newtonians with field coma , you have to accept compromises , but as we all know, many astro-eyepieces are comprised here as well.
All Carl Zeiss eyepieces sold by APM-Telescopes are delivered with a 1.25" alu-barrel, black anadized and applied with a 1.25" filter-thread. For each Carl Zeiss eyepieces we can sell you the optional high rubber-eye-guard.
Most modern Astro-Eyepieces have a multicoating which produce at the eyeside a reflection ging back to the eyes if straylight enter the eye-surface, this is hurting at day time and solar-observations and you loosing contrast and details. This Carl Zeiss eyepieces have such optimized optical design and combined with the modern Zeiss T* MC coating you are not able to discover such reflecting problem. Therefore this Carl Zeiss eyepieces are the best we have found on the world market for observing during the daylight natural objects and most important the sun in white light and h-alpha light.
The E-PL Series differs from the PL-Series mainly due the photografic flat-field correction.
This Carl Zeiss eyepieces can be upgrated ( also afterwards) with Carl Zeiss made cross-hair-inserts, reticle-micrometer, measuring-glas-plateand measuring and counting plate , which will be very useful for measurements of astronomical objects.
the 16 mm is at present exchange rate : US $ 420
the cheapest version of the 25 mm ( more expensive means larger FOV ) which is a updated glas of the famous TMB 25 mm aspheric ortho cost US $ 235
the 10 mm is US $ 495
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Based on the 25mm I have here, I would agree that these match the ZAO orthos, at 3 elements I suspect the 25mm may do even better. The 25mm I have has the OEM 44-45 degree FOV and it works very well out to the edge, almost perfect at f/8. Coatings appear to be equal to the best ep's I've used, ZAO, AP SPL, etc.
I bought this 25mm in early 2010 (***edit, it actually 2008). It is marked 44 42 31 on the back and E-Pl 10x/20 on the front. The case was marked "Made in Germany". I'm sorry to hear it's now "44 42 32" and made in China. The German-made one only cost a little over $200 when I ordered it.
My 16mm says W-Pl 16x/16 (45 50 48) on it and is much older. It's a great ep but the coatings aren't as good as my 25mm. The new 16mm pictured above doesn't have the "W", maybe it's not the same wide field (54 deg)?
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Yes. I have 4 Zeiss 25mm triplet aspheric, and they are the most confortable eyepieces I have. Reason being just right eye relief, and not wide field.
The problem with these triplets is that they show significant astigmatism off-axis, but on axis there is no better eyepiece. With 3 elements only it is not possible to achieve full corrected 50 degrees. Not even with 4 elements it is possible.
***However*** the amazing thing about these eyepieces is that when barlowed they magically get a perfect full-corrected field. This makes these eyepieces the better eyepieces in the world for binoviewers, specially the Baader/Zeiss one I have. This is because the binoviewer is supposed to be used with a compensator or AP BARCON.
So, in a binoviewer we get the impossible, a perfect corrected field with only 3 elements. And this also helps to compensate for all the extra glass in the binoviewer.
This is why I have 4 of these eyepieces. Two are permanently in the binoviewer. No eyepiece changing in binoviewer for me. Also as Roland says, we should use only low power eyepieces in binoviewer so that we do no magnify prism errors. I change bino maginifaction by changing barlows.
The other two are for using when I want the best transmittance and on axis image in the world at 25mm, in my bino scope. And if I barlow them, I get an excelent Zoom eyepiece (changing distance from eyepiece to barlow), with only 5 elements total.
I am now about to receive another pair of these, now a 16mm pair. Following what has been told here, these are likely made in China. We will see how good they come.
Please note that only a few of the Zeiss microscope eyepieces are triplets. The elements range from 6 to 3. The 16mm I am about to receive have 5 elements.
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