Which is copy? Biogon or Jupiter 12

[Mustafa Umut Sarac]

I read somewhere Russian lens designer Rusinov is the father of Biogon concept. So which lens is the father of other ?

Umut

[jmcd]

The J-12 is the copy, I am pretty sure.

[André E.C.]

Well, not quite far from truth, yet, not really so!

Indeed, in 1951, Dr.Ludwig Bertele, based his Biogon design (second and current form) on a double ended reversed-telephoto objective design, patented by M.M Roosinov in 1946. Which consists of a central positive structure with one or more large menisci at each end making a roughly symmetrical arrangement.

The Zeiss design had two menisci at the front and a single strong meniscus element at the rear. The distance from the element to the plane of the film is very short to lower distortion levels and increase contrast, therefore interfering with the mirror on SLR designs.

A master patent wasn't possible for this design, and many other companies embrace this excellent optical disposition, examples are Schneider's Super Angullon, with one menisci at each end, the Wild Aviogon and the Hologon developed by Dr.Erhard Glatzel in 1966 ( in reality, the Hologon it's a modification of the Biogon design).

So no, M.M Roosinov just created a design which gave the base to another concept.

Surelly, Bertele is the creator of the Biogon design!

[Rol_Lei Nut]

The first Biogon was a 35mm f/2.8 made in 1935.

The Jupiter is is apparently a very close copy, slightly tweaked in order to make it less sensitive to construction tolerances (so I've heard).

[df cardwell]

Bertele designed the first Contax Biogon, a variation of the triplet design; it is a cousin of his Sonnar.
The Jupiter is the same lens. It is not a wide field design, and will not fit on post war Contax cameras.

The second lens by Bertele named Biogon is the postwar Zeiss design that IS a wide field design that is drawn from the same principle of Roosinov used to give correct illumination in the corners of a wide field lens.

[Xmas]

A J12 in LTM is cheap, there is a large £$ step to the next lens option the Cosina Voightlander f/2.5 35mm.

[cmo]

A J12 in LTM is cheap, there is a large £$ step to the next lens option the Cosina Voightlander f/2.5 35mm.

Guess why:

1. The J12 is a copy of the pre-war Carl Zeiss Biogon 3.5cm f/2.8 for the Contax, a design from the 1930s, built between 1950 and 1960, whereas that Voigtländer lens was introduced in 2004.

2. The J12 was built according to russian manufacturing standards whereas Cosina is good enough to build lenses for Zeiss these days.

3. Both.

You might consider a Summaron 35mm, they sell for low prices today.

[Xmas]

Guess why:

1. The J12 is a copy of the pre-war Carl Zeiss Biogon 3.5cm f/2.8 for the Contax, a design from the 1930s, built between 1950 and 1960, whereas that Voigtländer lens was introduced in 2004.

2. The J12 was built according to russian manufacturing standards whereas Cosina is good enough to build lenses for Zeiss these days.

3. Both.

You might consider a Summaron 35mm, they sell for low prices today.

Hi

My J12 in LTM serial number said it was made in '91. It was a reasonable lens, and nearly as cheap as the LTM to M adapter ring.

Cosina or the Russians can/could employ whatever build standard they chose, e.g. at the beginning of WWII the T34s (medium tanks) were beautiful little tanks, the last one they were able to make in Stalingrad while the storm troopers were assaulting the next building may have cut some corners. But I'm sure it gave a good account of itself, in combat.

Cosina have made lenses and bodies for other suppliers than Zeiss.

The Summarons are nice lenses, the 35mm f/2.8 a real good performer, but an optically mint one will be more expensive than a CV 35mm f/2.5 by some margin, they are in the London shops, the collectors snap them up...

Noel

[cmo]

Hi

My J12 in LTM serial number said it was made in '91. It was a reasonable lens, and nearly as cheap as the LTM to M adapter ring.

Cosina or the Russians can/could employ whatever build standard they chose, e.g. at the beginning of WWII the T34s (medium tanks) were beautiful little tanks, the last one they were able to make in Stalingrad while the storm troopers were assaulting the next building may have cut some corners. But I'm sure it gave a good account of itself, in combat.

Cosina have made lenses and bodies for other suppliers than Zeiss.

The Summarons are nice lenses, the 35mm f/2.8 a real good performer, but an optically mint one will be more expensive than a CV 35mm f/2.5 by some margin, they are in the London shops, the collectors snap them up...

Noel

You are right, it was also built later, but in a different company named LZOS.

The problem with build quality is that the Soviets were really strong at building military equipment, and that includes quality control. (Russia is still one of the three biggest countries in terms of weapons exports.) Consumer goods for the average Iwan have never been a major focus for Kremlin potentates.

I remember times when Cosina was a maker of cheap 3rd party lenses. They have come a long way, and some of their own lenses are really good, too.

Regarding London and Summarons... well, London IS expensive, and 'mint' items from the 1950s are a costly hobby. But I often see acceptable Summarons for acceptable prices.

[Xmas]

You are right, it was also built later, but in a different company named LZOS.

The problem with build quality is that the Soviets were really strong at building military equipment, and that includes quality control. (Russia is still one of the three biggest countries in terms of weapons exports.) Consumer goods for the average Iwan have never been a major focus for Kremlin potentates.

I remember times when Cosina was a maker of cheap 3rd party lenses. They have come a long way, and some of their own lenses are really good, too.

Regarding London and Summarons... well, London IS expensive, and 'mint' items from the 1950s are a costly hobby. But I often see acceptable Summarons for acceptable prices.

Hi

My records indicate the

J12 was 40 GBP in caps, mint
CV 35mm f/2.5 classic 160 GBP, ditto + box etc.
CV 35mm f/2.5 pan 140 in opt hood and caps, ditto

How much can you get Summarons for here resonable optics 300 or more. E.G. Ivor of Red Dot one of our advertisers

http://www.reddotcameras.co.uk/produ...oducts_id=1686

325 GBP

Noel