Heavens Above
sage
Reged: 01/25/09
Loc: Bristol, UK
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Zeiss 25mm Aspheric Ortho or Brandon 24mm?
#4383662 - 02/13/11 02:54 PM
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Hi
Which do you think would be the better, Zeiss or Brandon. I am not talking about the Zeiss ZOA orthos (I know they are the best) but this one http://www.apm-telescopes.de/triplet-aspheric-orthoscopic-eyepiece_proinfo_86137.html
They will be used with my Mewlon in my binoviewer and mainly for planets.
Actual experience/opinions of either would be great.
Thanks
Tim
Edited by Heavens Above (02/13/11 03:36 PM)
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vahe
professor emeritus
Reged: 08/27/05
Loc: Houston, Texas
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: Heavens Above]
#4383778 - 02/13/11 03:46 PM
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Which do you think would be the better, Zeiss or Brandon. I am not talking about the Zeiss ZOA orthos
Actual experience/opinions of either would be great.
Not much help as I am not familiar with Zeiss aspherics.
I have a brand new pair of 24mm Brandons and compared them to 25 ZAO-1 in Zeiss viewer, the scope was a TEC Mak 200/20.
Using Jupiter as test object at about x200 Brandons were every bit as good as the ZAO, both produced black sky right up the planets disk, very little glow around planets bright disk. These 24mm Brandons offer a much wider view than the Zeiss, both produced sharp images across 80% of their respective fields with the incoming f/20 light cone.
Overall ZAO is just a tiny bit better, but we are talking splitting hairs here and to see the advantage a very stable seeing would be needed.
The only other eyepiece that outperforms both of these on planets is the 34 ZAO-1.
Vahe
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houser23
sage
Reged: 10/26/09
Loc: Rocklin, CA
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: vahe]
#4384780 - 02/13/11 11:32 PM
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I can't attest for the Zeiss eyepieces but I can for the 24mm Brandons.
The Brandons have given me more for contrast than any Ethos and have generally outperformed any eyepiece I have ever looked through, so I may be biased but I know quality when I look through one.
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Heavens Above
sage
Reged: 01/25/09
Loc: Bristol, UK
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: houser23]
#4388764 - 02/15/11 06:41 PM
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Thanks guys. Anyone with experience of the Zeiss?
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5u4
super member
Reged: 04/27/06
Loc: FL
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: Heavens Above]
#4388791 - 02/15/11 06:58 PM
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I've owned the APM Zeiss Aspheric ortho & the TMB version as well as the Zeiss ZAO-I & several Brandon 24mm's over the years. I'd be perfectly happy with the Brandon 24mm over the Aspheric, mostly due to the edge of the FOV performance is not the greatest in the Zeiss. The ZAO-I is the best of the bunch IMO.
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dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: Heavens Above]
#4389148 - 02/15/11 09:59 PM
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got no experience myself with the Zeiss 25 mm aspheric, but I do know that in reality it is the E-Pl 10x/20 Zeiss Microscope eyepiece (44 42 31) converted from it's original 30 mm barrel to the 1 1/4 inch format (25 mm focal length, 20 mm eyerelief).
(By the way, you can buy it at the online Zeiss micro-shop
for € 233,- , while Markus Ludes charges € 339,- ).
The author of this CN article has nothing but high praise for the same eyepiece (44 42 36, which is optically the same eyepiece as the 44 42 32, except that it sports a 25 mm eyerelief!(by using higher index glass types)).
All other reports I've read seem to like it a lot:
See this CN thread
Here you can find data of light-throuputs of many eyepieces, actually measured. You'll notice that the 25 mm Zeiss aspheric three-lens eyepiece has the highest overall transmission of ANY eyepiece listed (alas, no Brandons measured).
Regards,
Ralph
Edited by dothead (02/15/11 10:49 PM)
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dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: 5u4]
#4389264 - 02/15/11 10:48 PM
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5u4,
so, except for edge perfomance, you'd rate sharpness & contrast of the Zeiss & Brandon the same ?
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5u4
super member
Reged: 04/27/06
Loc: FL
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: dothead]
#4389644 - 02/16/11 06:19 AM
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I'd say the Aspheric & Brandon have similar performance in the center with the nod going to the Zeiss for slightly more pin-point stars, never used it for planets. The coatings on the Zeiss are a very transparent olive color & likely lets more light through. They have a very different feel to them though, the Ziess with more apparent eye-relief compared to the eye-cup version Brandon.
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PJ Anway
Carpal Tunnel
Reged: 06/04/03
Loc: North Coast
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: 5u4]
#4389769 - 02/16/11 08:27 AM
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I purchased two of the Zeiss 25mm aspheric orthos from Markus when the first came out several years ago. It is one of my most used eyepieces. In my f/10 refractor the stars are pin-points to nearly the edge. Contrast is excellent and scatter is well controlled. The fact that I still have them says a lot. I don't keep eyepieces that I don't love to use.
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Scott99
Carpal Tunnel
Reged: 05/10/07
Loc: New England
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: PJ Anway]
#4392361 - 02/17/11 10:59 AM
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this is one comparison that is tough for the Brandons. I've had a few different versions of the Zeiss ep in question and it's simply superb. The glass and multicoatings are the absolute best, only equaled (but not exceeded) by the ZAO's and AP SPL's that I've had.
Is it better than the Brandon? My response would be it's better than ANY other 24-25mm eyepiece. It has only 3 element of the best glass and coatings money can buy. The stars are tiny pinpoints and sky is as black as it gets.
with regards to the edge of field issue, the Zeiss 25 performs very well to its designed 44 degree spec. When APM mounts the glass in new barrels with 55 degree AFOV the edge of field drops off dramatically after 44 degrees.
For that reason I feel the best option is to order the ep (with long eyeguard accessory) from the Zeiss website and then get your own 1.25 inch barrel sleeve made. ($35 from Precise Parts, and they already know the specs). The ep will have 44 degree AFOV and at f/8 it's almost perfect to the edge.
you're in for about $250 this way and you get an ep that equals the performance of the orthos that sell for $500-$700.
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Svezda
scholastic sledgehammer
Reged: 06/01/07
Loc: Texas
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: dothead]
#4395828 - 02/18/11 08:45 PM
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Here you can find data of light-throuputs of many eyepieces, actually measured. You'll notice that the 25 mm Zeiss aspheric three-lens eyepiece has the highest overall transmission of ANY eyepiece listed (alas, no Brandons measured).
Regards,
Ralph
Ralph,
Wow, this in part explains my 'Zeiss Out of Body Experience' with this eyepiece. I knew it was very special when my view of the M42 region (with my TEC140 in a very dark sky) looked to me like a long exposure image - I could see the whole loop of nebulosity very easily and the contrast and sharpness were just amazing.
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dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: Svezda]
#4396270 - 02/19/11 01:44 AM
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sounds super-duper-out-of-this-world...
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RodgerHouTex
Pooh-Bah
Reged: 06/02/09
Loc: Houston, Texas, USA
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: dothead]
#4397461 - 02/19/11 04:52 PM
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Okay. I would like to order the Zeiss and believe the one I want is the 444232 which is the E-PL 10X/20 Br. Foc. eyepiece. Is that correct for $223 on Zeiss online? By the way what does E-PL and Br. Foc. mean.
Also I spent all afternoon trying to find some description of the various microscope eyepieces that Zeiss has and had no luck. If you click on the Eyepiece ... in blue, all you get is a picture. If anyone knows where the descriptions might be and what the nomenclature means it would be very helpful. I can't believe someone would drop $1500 dollars for one of these eyepieces and not know what they are buying.
Thanks.
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PJ Anway
Carpal Tunnel
Reged: 06/04/03
Loc: North Coast
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: RodgerHouTex]
#4397983 - 02/19/11 08:26 PM Attachment (60 downloads)
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The Zeiss 25mm aspheric ortho (the Zeiss version of the eyepiece designed by Thomas Back), the original that Markus Ludes used to sell is pictured below with case:
I don't believe that it is available new anymore.
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pbsastro
sage
Reged: 03/21/07
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: PJ Anway]
#4398097 - 02/19/11 09:26 PM
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The Zeiss 25mm aspheric ortho (the Zeiss version of the eyepiece designed by Thomas Back)
Designed by Thomas Back??? You mean the version with Thomas Back name so that it would sell well in the US.
As a basketball player that appears in the box of some corn flakes, designed the corn flakes.
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PJ Anway
Carpal Tunnel
Reged: 06/04/03
Loc: North Coast
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: pbsastro]
#4398257 - 02/19/11 10:54 PM
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Quote:
Quote:
The Zeiss 25mm aspheric ortho (the Zeiss version of the eyepiece designed by Thomas Back)
Designed by Thomas Back??? You mean the version with Thomas Back name so that it would sell well in the US.
As a basketball player that appears in the box of some corn flakes, designed the corn flakes.
I guess I should have worded that differently. I was referring to the eyepiece that TMB/APM included with the monocentrics. It used the same Zeiss lens, but the eyepiece itself was a "design" of TMB/APM to match the look of the monocentric.
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dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: RodgerHouTex]
#4398495 - 02/20/11 01:48 AM
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Yes, I'd order the 444232 model.
"E-PL Br. foc."
= "Epi-Planar; Brille focal"
translation:
"hyper-flat field; for eyeglass wearers, with focusing mechanism"
re the nomenclatura - maybe you want to read the article I linked, it's described therein.
To calculate the focal length of a microscope eyepiece, you divide 250 by the magnification factor given.
For the Zeiss Aspheric it's 250/10x = 25 mm
For a 16x eyepiece, the focal length is 15.6 mm.
the second number of a microscope eyepiece designates it's eyerelief.
A 10x/20 eyepiece has an eyerelief of 20 mm.
Sorry, don't know where to obtain the eyepice design descriptions.
Honestly, I guess the microscope guys (lab personell, doctors,...) don't care a damn about what the exact design of their eyepieces are (we amateur astronomers are more discriminating  )
I'm sure they're basing their purchase decision solely on the first-class reputation these eyepieces enjoy (THE standard against which every other microscope eyepiece is measured). Guess eyepiece prices are secondary to this clientel, a big lab would churn out more than $ 1000,- per eyepiece for the 25 mm eyerelief version to ensure their employees have the maximum viewing comfort during the long hours spent over the microscope binoviewer.
Regards,
Ralph
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pbsastro
sage
Reged: 03/21/07
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: dothead]
#4398679 - 02/20/11 06:12 AM
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the second number of a microscope eyepiece designates it's eyerelief.
A 10x/20 eyepiece has an eyerelief of 20 mm.
I think the second number is field stop, not eye relief. That is said in the article an also by Markus Ludes on AP yahoo group (09-06-2008).
I guess for medical lab people it is important to know the size of things they are seeing, so the field stop divided by the total microscope magnification gives them the field real size. In astronomy we use angles instead because stuff is at different distances, therefore real size cannot be told by apparent size.
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RodgerHouTex
Pooh-Bah
Reged: 06/02/09
Loc: Houston, Texas, USA
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: pbsastro]
#4398761 - 02/20/11 08:15 AM
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Thanks a great deal for the clarification Ralph. I went ahead and ordered the eyepiece. I'll be very interested in seeing how it performs.
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dothead
scholastic sledgehammer
Reged: 08/13/08
Loc: Heidelberg, Germany
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Re: Zeiss 25mm Aspheric Ortho or Brandon 24mm?
[Re: pbsastro]
#4399404 - 02/20/11 02:00 PM
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of course you're right, my bad, sorry for the mixup.
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