Info regarding an antique large format lens.

[Andrey Donchev]

Hi, I bought a brass lens on which I can not find any information at all.

On the brass barrel is written: PHOTO-HALL, Paris, No 11.015
The apertures are f8-64
It consists of two lenses. Convex-concave lens on the front and mirrored convex-concave lens on the back.
The focal length, although not mentioned, is 240mm by my own measuring.

Any information will be highly appreciated! Thank you very much in advance!
Andy

 

[Ole]

I can't find anything about this, but look for a weak reflection in each of the lens cells. If that is cemented interface is strongly curved the same way as the other surfaces (reflections move the same way when the lens is tilted, but much slower), it is most likely an Aplanat.

With f:8 as the max aperture this is the most likely construction. Anastigmats are (mostly) not wholly symmetrical, and Periskops (2 elements in 2 groups) were mostly f:12 or f:16.

 

[Andrey Donchev]

Hi, Thank you very much for this answer, Ole! The lens sells are not doublets, or triplets, but single lenses. I did disassemble them and they are single glass elements!

 

[Ole]

Does it have "ordinary" f-stops, or some other system? E.g. 8-16-32-64?

If that's what it has, it's probably the "French System", somewhat similar to the Universal System used in USA at that time. Or the Stolzesche System, used in Germany by some makers...

 

[Andrey Donchev]

Normal f-stops. 8, 11, 22, 32, 44, 64 with 12 blades.

 

[Ole]

Then it's an f:8 Periskop-type lens. Used wide open it will be very soft and "dreamy", getting sharper with stopping down. These were made as portrait lenses, or in one case (Voigtländer W.Z.) as a soft enlarger lens.

The W.Z. is a great portrait lens BTW, I would expect yours to be just as fine

 

[Andrey Donchev]

Thank you very much, Ole!

 

[Abbazz]

Hi, I bought a brass lens on which I can not find any information at all.

On the brass barrel is written: PHOTO-HALL, Paris, No 11.015
The apertures are f8-64
It consists of two lenses. Convex-concave lens on the front and mirrored convex-concave lens on the back.
The focal length, although not mentioned, is 240mm by my own measuring.

Andy,

Photo Hall was one of the largest distributor of photographic equipment in France in the first half of the 20th century. As far as I know, camera and lenses sold under the "Photo Hall" brand were made by various manufacturers, as Zeiss or Hermagis for lenses.

You can find some info on Photo Hall on Sylvain Halgand's site (in French):
http://www.collection-appareils.com/photo-hall/html/chronohall.php

Cheers,

Sebastien

 

[Andrey Donchev]

Merci beaucoup, Sebastien!