Post War lens designs

[snaggs]

We know that when german patents were invalidated at the end of WW II, that the rest of the world were able to copy all their designs, and apparently most Japanese lenses today are all still derived from these designs.

I've also read that Zeiss (and Leica??) had to "re-invent" the lens to come up with something better since their patents were gone. Can someone please enlighten us to what the original designs were, and what the equivalent new designs were by Zeiss (and Leica).. Are any of them really new? How are they better?

Daniel.

 

[wlewisiii]

I think, from my reading, that the story of lens design is simply one of slow improvement - refining the designs, different glasses, new coatings and so forth - rather than anything radically new. Many of the basic designs are still the same ones that existed at the start of WWII. Some (the Planar comes to mind) were only practical with improvements in coating that have been created since then, but ultimately there are only a small handfull of designs that form the basis of the vast majority of lenses.

As far as better, isn't that dependant upon the photographer's needs?

William

 

[Pherdinand]

There were a few important moments within the 150 years of lens design (ok let's not get back to the Vikings). Like William says, introducing new types of 'weird' glasses (in the 1920-1930's i think) and plastic elements, invention of antireflection coatings, aspheric lens surfaces (quite complicated to make them), computer aid in lens design speeding up the process and increasing accuracy immensely. All these are equally important in my view. The designers got more and more factors to play with and all this helped to get quicker, cheaper and/or better results especially on the mass-produced market.

If you're interested in these stuff, try to get a book of Rudolf Kingslake related to lens design history, or even better, the book of Sidney F. Ray from 2000, called 'photographic optics design' or stg like that. Lotsa information written in a digestible way.

 

[jlw]

We know that when german patents were invalidated at the end of WW II, that the rest of the world were able to copy all their designs, and apparently most Japanese lenses today are all still derived from these designs.

I've also read that Zeiss (and Leica??) had to "re-invent" the lens to come up with something better since their patents were gone. Can someone please enlighten us to what the original designs were, and what the equivalent new designs were by Zeiss (and Leica).. Are any of them really new? How are they better?

Daniel.

I'd never heard or read of any blanket "invalidating" of German patents after the Second World War (except maybe in specific cases involving war reparations.) There were a lot of trademark lawsuits after Germany was partitioned into eastern and western zones (Carl Zeiss and Exakta being two photographic names involved) so I had assumed that other intellectual-property laws were still in force as well. Do you have some references on where I can read up on this?

Anyway, although specific lens design features may be patentable, the overall structure of a lens generally is not -- lens design is based on the properties of light and refractive materials, so there are only so many ways to design one that will work, and anyone who does the math is likely to come up with a similar answer given the same set of initial constraints.

So (for example) a "Sonnar-type" or "Heliar-type" lens may not have been copied directly from a specific Sonnar or Heliar design; instead, the designers arrived at a similar solution because they were trying to solve similar problems using similar techniques.

Since the math behind optics was pretty fully understood by early in the 20th century, big jumps in the progress of lens design after that are more likely to have come from other areas of technology: for example, improved types of glass (giving the designer more flexibility in solving problems); mass-produced aspheric surfaces (ditto); lens coating (which gave practicality to designs that previously would have been too flarey); or the use of computers (which make it possible to use more ambitious or exotic designs by allowing designers to solve more calculations to reach the best compromise.) Let's also not forget progress in the overall area of precision machining, which allowed lenses to be assembled more consistently and made it practical to improve lenses using mechanical techniques such as floating elements.

These types of improvements may be one maker's exclusive property when they first appear, but the technology behind them is generally so broad that a lot of people soon will develop similar capabilities even if a specific implementation is protected by a patent. The overall effect, as someone else posted, is one of overall general progress, rather than of one or two companies that possess "the secret" being able to outdistance everyone else. And in my view, as gracious living diva/greedy jailbird Martha Stewart likes to say, "It's a GOOD thing!"

 

[Huck Finn]

Daniel, you are correct that German lens designs were copied by the Japanese after the war. As others have mentioned, there were a number of lawsuits over this dispute. There is an excellent article on this topic, "Postwar Camera & Lens Design Thievery", by Marc James Small of the Zeiss Historical Society, which explains the intricacies of this complicated situation. Here is the link:

www.dragonsgate.net/mbell/leica/thievery.htm

By the way, there was no need for the German companies to discontinue their pre-war Lens designs. Carl Zeiss, for example, continued to produce their traditional Planars, Tessars, Sonnars, etc. The most revolutionary post-war Zeiss design was the Biogon, developed in the early '50s, but its development had nothing to do with loss of patent rights to other lens designs. It was a break through design to meet the challenges of expanding photographic capabilities.