Vintage lens question

[james_hock]

Hello all. I wanted to know how I can find out the image circle or coverage at 4x5 of various vintage lenses? I would quite like to try a vintage lens on my 4x5 for a project I am planning. One example I have seen is the Steinheil München Anastigmat Actinar 4.5. There are other models by Steinheil München available but I do not know if they are 1/4 plate, 1/2 plate, 4x5 etc. Is there a database of old lenses? Can anyone recommend some to try? Thanks James

 

[Ian Grant]

Coverage is the area of acceptable sharpness which is not the same as the area illuminated. The definition of acceptable sharpness seems to vary between manufacturers and no precise figures are given although I guess something could be derived from data sheets.

With standard lenses the rule of thumb is that the focal length is roughly the same as the diagonal of the smallest format the lens will cover and also allows slight movements.

A lens fora Quarter plate camera will just about cover 5x4 stopped down well, 135nn or longer. Half plate / 13x18 lenses will easliy cover 5x4 and are usually around 200mm/8".

Coverage and sharpness also depend on lens design, is listed as a Cooke triplet, so softer at wide apertures than a Tessar or Plasmat (sharpest at wider apertures), triplets make good portrait lenses.

Ian

 

[james_hock]

Wow thanks - where can I learn more about lens design and function?

 

[Ian Grant]

A 50mm Actinar was used on the 35mm Dolly, and also a 6" on the KW Pilot. KW (or their UK importer Sands Hunter) were using Steinheil lenses by the late 1930's. I have a 105mm f4.5 Steinheil Doppelanastigmat Unofokal on a 6.5x9 KW Patent Etui, it's a Dialyte designed in 1906 so less contrast than a triplet (more internal air'glass surfaces).

Ian

 

[james_hock]

Thanks Ian

 

[manualcamera]

The Schneider Actinar is a triplet lens, the KW Reflex-Box camera (1936) had an Actinar 105mm f/4,5