Beck Lenses, Biplanat

One last note: the book states that the name Biplanat was used to indicate that the lens was an Aplanat, but one stop faster than the regular f/8 Aplanats.

Charley

Someone alleged Beck re-sold Steinheil Extra Rapid Aplanats to get around
Dallmeyer's patent.
As long as the beast will cover 4x5.
That is 4x5 at infinity, or are we talking about for group shots closer to?

I just bought a 3rd Edition of the book "Photographic lenses, a simple
treatise" by Conrad Beck & Herbert Andrew.
The Unicum shutter housing the Beck lens is not so healthy. Has anyone else
got one and managed to have it timed on a test rig?
With mine 1 sec is around 1/2 sec, 1/2 sec is around 1/3, 1/5 is about right
and 25th, 50th and 100th/sec fire at 50th.
I am hoping that this will be enough to asses the lens as a candidate for
re-mounting.

On 25 Feb., 20:51, "Neil Purling" wrote:
I just bought a 3rd Edition of the book "Photographic lenses, a simple
treatise" by Conrad Beck & Herbert Andrew.
The Unicum shutter housing the Beck lens is not so healthy. Has anyone else
got one and managed to have it timed on a test rig?
With mine 1 sec is around 1/2 sec, 1/2 sec is around 1/3, 1/5 is about right
and 25th, 50th and 100th/sec fire at 50th.
I am hoping that this will be enough to asses the lens as a candidate for
re-mounting.

I have the same shutter speeds (1sec ist around 1/2 sec).
My camera is just obsolete.
UNICUM
Bausch & Lomb OPT. 00. Pat. Jan. 6, '91.
Bausch & Lomb Optical Co Rapid Rectilinear
I bought it in Dez 07 ebay, Germany (Hamburg)