Narrow field, non-telephoto lens design question

[genotypewriter]

Hi everyone,

If we assume that 45-60 degrees of coverage as neither wide or long, are there lenses with significantly narrower fields (e.g. 30 or less) that are non-telephoto designs (in any format)? Also the narrowing of the field must be achieved by glass rather than by a baffle, etc.

Thanks in advance.

Guy

[Dan Fromm]

Go here http://www.dioptrique.info/base/listes/liste_ordinale.HTM and work your way through the lists. There are many non-tele designs with low coverage.

Go here http://www.lallement.com/pictures/files.htm and download the 1963 GOI catalog, which lists most lenses made in the Soviet Union up to 1963. One of the tables towards the front sorts them by angle covered.

[jb7]

Petzval ?

[Emmanuel BIGLER]

are there lenses with significantly narrower fields (e.g. 30 or less) that are non-telephoto designs (in any format)?

All telescope lenses, either refractors or reflectors (newtonian telescopes) belong to this category, but their angular field is quite narrow, I would say, about 5°.
The traditional refractor design is known since the XVIII-st century: the achromatic doublet, this design can be found in the Rodenstock Imagon soft-focus lens which is, to some extent, a typical narrow-field non-telephoto lens.

The advantage of reflectors is that a single concave mirror is free from chromatic aberrations, but for "wide-field" reflector lenses in astronomy, i.e. what we photographers would consider as a "narrow field", more complex reflector/refractor designs are used combining a concave mirror and other aspherical lens elements like in the Schmitt or Schmitt-Cassegrain designs.
"wide field" telescopes were used for mapping the sky at a time when only photographic plates and films were used as image detectors. Even if some automatic scanning of the sky with a digital image sensor is now in use, I think that wide-field telescopes are alive and well.

In 35 mm photography, Leitz had a Telyt lens which was a non-telephoto design: quoting from memory, this was an apochromatic cemented triplet.

Paparazzi-style long focal lengths in 35mm- and medium-format photography are probably all telephoto designs, the Telyt being, to the best of my knowledge, one of the few exception for long, non-telephoto, general-purpose photographic (i.e. non-telescope) lenses still commercially available at the end of the last century.

In LF photo if we do not take into account long dialyte designs like apo-ronars given for about 40° of angle (but they can be used at the centre of the field, since their image quality is so good), we have the Nikkor-M series which are tessar designs optimized for the centre of the field, hence intended for use for angular fields smaller than 50°; actually the specs for the 200 mm Nikon-M say : 45°@f5,6 to 55°@f22 so this is not 25°, and not really very different from any classical tessar design.

[Dan Fromm]

Emmanuel, don't forget Century Precision Optics' TeleAthenars. People who take trade names seriously believe that these monsters are telephotos but they're really achromatic doublets. All for small formats. And Century is now owned by Schneider.

[Emmanuel BIGLER]

Thanks Dan !

Hence our list "quoting from memory" now contains 2 items, TeleAthenars and Telyts.

BTW, what were the lenses in use in Big Berthas ? (http://petapixel.com/2014/04/25/a-look-back-at-the-120lb-action-camera-known-as-big-bertha/)

[Dan Fromm]

Lenses for Big Berthas? Whatever was available, most Berthas seem to have been improvised. Eve Girard has a Bertha designed by Jim Frezzolini that's fitted with a 500/4.5 Tessar. I believe, with practically no data to support the belief, that most Berthas used tele lenses extracted from aerial cameras. My failed Baby Bertha uses process lenses; the two longest are a 610/9 Apo-Nikkor (46 degrees) and a 900/10 Apo-Saphir (40 degrees).

Come to think of it, the OP should look at http://archive.org/details/USAF_lens_datasheets , which has a few narrow angle non-teles.

[Emmanuel BIGLER]

http://archive.org/details/USAF_lens_datasheets

Thanks, Dan, for the link.

If I understand well, US regulations read as follows
"Documentation relative to military equipement, paid in the past by the US taxpayer, and once duly de-classified, shall be available for free, even to non-US taxpayers".

I already knew about this generous attitude for Civilian things like Prokudin Gorskii's tri-color images, but it seems to apply also to documention of old aerial cameras! Great!

[genotypewriter]

Thanks everyone for the informative replies and links to resources. Lots of food for thought.