Tachonar 75mm F1

[ssoul]

Hello,

I'm new to this forum and recently acquired a lot of lenses some of which may belong to the Large Format category but I'm not sure.

The first one I'm researching is a Astro Berlin C Tachonar 75mm F1 as seen here (http://www.exaklaus.de/astrotachonar.jpg)

The lens has no iris and no focusing mechanism.

I wonder if someone would now what mount this is, and it's coverage

Also in terms of pricing, other versions of this lens are priced very low as in here (http://www.ebay.com/itm/Hochwertige-Linse-Objektiv-Astro-Berlin-Tachonar-1-1-75mm-/251711933344?pt=DE_Foto_Camcorder_Objektive&hash=item3a9b334ba0&nma=true&si=B4eAIzygDQaOdFjXm4j8o0GZl0Y%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557)

or very high as in here (http://www.ebay.com/itm/Rare-Astro-Berlin-Tachonar-75mm-f-1-0-Modified-to-Sony-Nex-Alpha-7-A7-Noctilux-/251558138556?pt=Camera_Lenses&hash=item3a920892bc)

How should I price this version?

Thanks,
Danny

[David R Munson]

Focus it on a piece of paper and point it out the window. Get something distant sharp, you'll see roughly what the coverage is.

[mdarnton]

If I were going to sell such a thing, I would price it like the one that sold, not the one that hasn't. Unless, of course, you, also, don't want to sell it.

[Tim Meisburger]

I don't think it is a large format lens. It looks like a projection lens.

[Dan Fromm]

It is a lens from an X ray machine. Tiny coverage, pretty useless for use as a photographic objective although I'm sure someone somewhere has adapted one of these or something similar to a micro 4/3 digicam.

About the equivalent Rodenstock lenses:

In his book The Photographic Lens (1968, Focal Press, London, New York. Originally published as Das Photo Objektiv, 1956, Friedr. Vieweg & Sohn Verlag, Braunschweig), Hans Martin Brandt explains that lenses such as Rodenstock's XR Heligons and TV Heligons were used in pairs for "presentation of the image formed on an X-ray amplifier tube screen to a larger audience via a television system. Conventional optical systems cannot satisfactorily project these images onto the photo cathode of a television picture tube and special optical designs are required for this purpose. …

While it would go beyond our scope to go into this specific application in exhaustive detail, the optical transmission of an anode image to a television system requires so-called tandem lenses. These are a combination of two lenses optimally corrected for infinity. They are arranged in such a way that the anode image is in the focal plane of the first lens, while the photo cathode tube of the television camera tube is in the focal plane of the second lens. …

In the first place this relay optical system must have the largest possible aperture. On the other hand geometric image corrections must be brought to an optimum …

Rodenstock suggest a number of their lenses as suitable for such tandem combinations. Recommended systems for the lens facing the X-ray image tube are the 100 mm Kinemar f/1.5, the 75 mm XR Heligon f/1.1 or the 50 mm XR Heligon f/0.75. The second lens for projection onto the final image plane can be a 32 mm Heligon f/1.3 (for 16 mm narrow gauge cine), the 70 mm Heligon f/1.4 (for standard 35 mm cine cameras) or the 50 mm TV Heligon f/0.75 for Vidicon cameras.”

[Carsten Wolff]

This lens covers 24x36 film format;- the Lens Vademecum refers to the 25mm version as a 16mm lens, the 75 covering FX and the 100mm version 6x6. I adapted a 65mm f/0.75 Astro-Berlin Tachon (different lens design entirely) to an SLR, achieving (with technical difficulty) infinity focus. Mine was very "luminous/soft" wide open, to put it mildly. Nothing to write home about.
Your lens in contrast (excuse the pun) was designed for general pictorial use....so you should have very nice results after adaptation via a short focussing helix.

[ssoul]

Thank you all very much for all this information; it was very helpful.
Danny

[Dan Fromm]

Tachonar

Das Tachonar ist ein extrem lichtstarkes (f1,0) Objektiv mit fünf alleinstehenden Linsen.[43] Das Design ist vom Zeiss-Sonnar abgeleitet.[44] Es wurde in wissenschaftlichen Anwendungen beispielsweise als Sammellinse in der Raman-Laserspektroskopie genutzt.[45][46] Üblich war ein Einsatz, um Bilder auf den Schirmen von Röntgengeräten oder Oszillographen auf Kleinbildnegativen festzuhalten. Diesem Zweck diente beispielsweise ein Tachonar f1/75 mm mit einem Bildwinkel von 36°.[47]

source: http://de.wikipedia.org/wiki/Astro-Berlin

Translation (by Google Translate):

The tachonar is an extremely high flux (F1.0) lens with five single lenses. [43] The design is from Zeiss Sonnar derived. [44] It was in scientific applications, for example as a converging lens in the Raman - laser spectroscopy . used [45] [46] usual was used to capture images on the screens of X-ray equipment or oscilloscope to mm negatives. This was the purpose, for example, a tachonar f1 / 75 mm with an angle of 36 °.

The article cites the original German edition of the H. M. Brandt book I mentioned above as the source of its information on the Tachonar. I couldn't find anything on it in the English edition.