Old meets new. 0.96" adapter arrived

[glennbech]

Since I have made a slight detour into classic telescopes on my way from imaging to visual astronomy I now have a small collection of 0.96" eyepieces. Some of them, especially my Zeiss's seem to be of good quality. I got my adapter today and have doen a quick shoot out. Please feel free to comment on my observation, and educate me and others on Eyepiece theory  Disclaimer: I am new to visual astronomy, I am very far from an expert on Eyepieces. Also feel free to comment on how to test eyepiecs! 

Vixen SLV 20mm vs Carl Zeiss 20mm Ortho 

Splitting Mizar. The Vixen SLV seems to produce a brighter image. Both eyepieces creates a clean split at 31 x magnification. The Zeiss is less tolereant for eye movement, a correct head position is needed to get pinpoint stars.  

Vixen NLV 10mm vs Carl Zeiss 10mm Ortho

Moon & Jupiter. Both Eyepieces seem to produce an image of equal quality.  

.. To be continued

 

 

[John]

Interesting initial findings

The Carl Zeiss Jena orthos have an excellent reputation.

[michael.h.f.wilkinson]

Interesting report. Just goes what modern coatings can do, if a multi-element design bests an older generation orthoscopic on transmission

[glennbech]

15 hours ago, michael.h.f.wilkinson said:

Interesting report. Just goes what modern coatings can do, if a multi-element design bests an older generation orthoscopic on transmission

After your post, I read up on coating here; http://www.astrosurf.com/luxorion/reports-coating.htm - interesting read. "Theoretically, an uncoated lens can lose about 4% of light transmission". Does the size of the eyepiece 0.96" vs 1.25" have anything to say when it comes to image brightness?

 

 

[Dude_with_the_tube]

Zeiss Orthos are in the top shelf of  planetary oculars and i cant see modern multi lens occulars will beat them in sharpness and contrast on planetary or doubles.Will get close,but not beat them.Also Zeiss are Magneisum coated and NOT un-coated.

0.965" versions are obviously older ones and where intended for refractors with focal ratio of F10-F15. But still these are coated and absolutely superb eye pieces.

Yes Vixen SLV and NLV will have better eye relief  (20mm) in comparison to orthos and thats possibly why you struggled to get your eye position right.It is in some sort a learning curve but not a steep one.

Image brightness has nothing to do with diameter of your eye piece.Its the size of your telescope unfortunately.But for planetary ,size isnt that important as planets are bright enough in most cases. 0.965" is just the older models and where superseded by 1.25" versions.

To really determine what eye piece is better,try doing critical observations of the same spot.For example a simple test for both eye pieces on Moon: Plato crater and compare how many craterlets you can see,any fine detail on crater walls etc.And then compare what eye piece gave you more of the fine detail.

Good luck and clear skies.

P.S. Good reading material about Zeiss 0.965" orthos: http://www.cloudynights.com/page/articles/cat/user-reviews/eyepieces/eyepiece-sets/carl-zeiss-jena-0965-inch-orthoscopic-eyepieces-r282

[michael.h.f.wilkinson]

The Zeiss Jena orthoscopics are MgF2 coated, meaning the have 99% transmission per surface. For four glass-air interfaces that means a total transmission of 96%. If the SLVs have 8 glass-air interfaces with state-of-the-art coatings, i.e. 99.8% transmission per surface, the total transmission would be 98.4%. In both cases I am neglecting losses due to the glass itself. 

I do wonder if this 2.4% increase would be readily visible. 

[Dude_with_the_tube]

also Michael,you need to take into account:

1.Polishing  and optical quality of the optical elements,where Zeiss where known for they very high standards.Not that i am trying to say Vixen are not up to the standards.

2.For planetary observations,less glass=better views where always the way to go.

3.Question i normally have is when vendors state:" State of the art coatings".What they mean with state of the art?? 

 

other than that,location,seeing conditions,optical quality of telescope ,diagonal etc etc will play they role too.Too many factors to take into account