TheSkySearchers

Hello all,

because of my curiosity, I have added to my collection of the astronomy eyepieces this ortho,
This orthoscopic astronomy eyepiece has a very simple lenses sequence (field stop - 1 - 1), the both lenses are narrow spaced biconvex.
The narrow field of view competes with that of the TMB Super-Monocentric.
The eye relief is not worse than that of the Abbe orthos.
The way how the lenses are mounted in an oversized drum reminds me of Stenheil in München, around 1907.


The ASTRO BERLIN has been founded in 1922 by Willy Bielicke, Astro-Gesellschaft Bielicke & Co.
The astronomy section of the company has been under H.I. Gramatzki, the designer of the first zoom eyepiece (Transfokator).




And on a side line to the Ortho, here is the Gramatzki's zoom eyepiece,

https://upload.wikimedia.org/wikipedia/ ... or.tif.jpg
Herewith it is likely, that the ASTRO BERLIN ORTH eyepiece has been aslo designed by Gramatzki, maybe even one of his first astronomy optics designs.

Best,
JG

Nice find!
Have you observed with it yet?

Very unique JG.
A nice looking addition to the collection and I look forward to your thoughts of it in use.
The Gramatzki zoom appears to be another intriguing design!

John Baars wrote: ↑Sat Sep 11, 2021 12:37 pm Nice find!
Have you observed with it yet?

Hello John,

not yet, today I took just the documentary pictures.
To use it on the elescope, the lenses would require cleaning.
Otherwise, I would not expect much from a symmetric aplanatic design eyepiece. I take it as a piece of history.

Best,
JG

Lady Fraktor wrote: ↑Sat Sep 11, 2021 4:55 pm Very unique JG.
A nice looking addition to the collection and I look forward to your thoughts of it in use.
The Gramatzki zoom appears to be another intriguing design!

Hello Gabby,

the zoom eyepiece design looks quite interesting, even if not parfocal across its zooming range.

The optics developments in the city of Berlin became somehow forgotten. And regarding the astronomy optics, it has been difficult to compete with Steinheil in München, and with Zeiss in Jena.

Best,
JG

Nice! Just how many vintage eyepieces do you have in your collection?

Very interesting history, and thank you for sharing so it is not lost, JG!

WilliamPaolini wrote: ↑Tue Oct 19, 2021 9:16 pm Nice! Just how many vintage eyepieces do you have in your collection?

Hello Bill.

some pictures from my collection are scattered around the world,
viewtopic.php?p=90079#p90079
viewtopic.php?p=90576#p90576
https://www.cloudynights.com/topic/7115 ... ittenzwey/

In total, my vintage eyepieces may be about 20, but lots of them are just the same design.

Thank you for asking,
JG

JG,

A vendor friend in UK gave me these a while back. He did not know anything about them but thought they were more than a century old. No identifying marks on them. The one on the right has a top cover on it (shown) which has an extremely dark glass. I am presuming it is a solar filter as way too dark for lunar. FL I think is fairly short though on the lenses under it.

Hello Bill,

these are very interesting eyepieces!

From outside, they are looking like from tactical optics - Flak, rifle scopes, theodolites, laboratory optics (refractometers, spectroscopes),
from the times between WWI and WWII, typically centered around 1932.
Their typical designs used to be König, symmetrical Plössl, Abbe ortho.

For sure, it would be interesting to see the optics design of these eyepiecesof yours.

Thank you for sharing,
JG

PS:
Otherwise, should you need some pics of the old eyepieces as illustrations for your new book on the eyepieces, and should I be able to help, then contact me.