[Leica] Lens Designs

[Marc James Small <msmall@roanoke.infi.net>]

At 11:35 AM 1999-01-11 -0800, Peter Kotsinadelis wrote:
>
>But when Rudolph (Zeiss employee) designed the Tessar as a modified lens
based on
>Taylor's Triplet (1894) was this borrowed?  Also, the Zeiss Biotar of 1911
>was a high-speed modification of the Petzval-lens, Dr. Petzval was employed
>by Voigtlander, did Voigtlander sell Zeiss this lens design? 
>Dr. Smakula's patent for a lens coating (patented in 1935) was based on the
>earlier findings of Josef von Fraunhofer, (1817) who noted that weathered
>surfaces enabled higher light transmissions, and those of Dennis Taylor
>(1904), an English optician who used an acid treatment to lower the
>refraction index of a surface.  
>Wasn't the Contax I of 1932 with its focal plane shutter very Leica-like in
>its design (borrowed design ideas perhaps?).


Zeiss controlled Goerz from 1919;  they purchased them outright when Goerz
was merged into Zeiss Ikon in 1926.  This was partly mandated by the
Versailles Treaty, which restricted Germany to a single optical glass
works, and the German government had selected Schott (Zeiss-owned) over
Goerz.  (This caused problems, incidentally, in Wetzlar, as Leitz had been
purchasing their optical glass from Goerz, and now had to go, hat-in-hand,
to Schott.)

Again, and again:  a BROAD approach cannot be patented.  A specific design
CAN be patented.  What the Japanese took were SPECIFIC designs, not broad
approaches.  That is, they took the actual physical dimensions, materials,
and so forth, to produce their gear.  A SCIENTIFIC PRINCIPLE (such as the
effect of weathering on light transmission) cannot be patented, a SPECIFIC
application of that principle CAN be patented.

To cover your specific points:

The Tessar WAS derived from Aldis' Stigmatic design, and this was reflected
in the Tessar's original name:  "Anastigmat".  Zeiss was careful to
distinguish the two designs, and Aldis accepted the distinction:  Aldis,
after all, had derived HIS design from Rudolph's original Anastigmat.  The
Tessar was not derived directly from any work of H Dennis Taylor, though
the Cooke Triplet you reference HAS been quite successful and examples are
still in production today.  The Voigtlander Heliar was a derivative of the
Cooke Triplet, though it clearly did not infringe on Taylor's patent, being
a development of some complexity.  See Kingslake, pp. 82 - 88 et 105 - 108.  

The Biotar was derived from HW Lee's Opic, as was the slightly earlier JSK
Xenon.  Again, neither lens infringed on Lee's patent:  he went on to
himself derive the famed Speed Panchro from the Opic.  Lee, in turn, may
have derived his unsymmetrical Opic from Rudolph's original symmetrical
Planar of 1896.  See Kingslake, pp. 122 - 123.   (HW Lee is sadly forgotten
today:  he was a phenomenally skilled designer and his life work is
extraordinary.)

Now, the Petzval design WAS stolen, and I'm glad you mentioned it!  Petzval
designed the lens without any contribution from Voigtlander, though he did
receive support from the Austrian Army, who assigned "Corporals Loeschner
and Haim and eight gunners skilled in computing" to assist his work, these
guys being the 1840 equivalent of a desktop PC.  When the designs were
completed, Petzval asked PWF Voigtlander, the head of the family-owned firm
of that name, then in Vienna and, in 1840, already some 84 years old!, to
produce and market this "Petzval Portrait Lens" for him.  Voigtlander did
so, with phenomenal success.  In 1849, when Petzval requested an
accounting, Voigtlander moved by night to Braunschweig, to avoid the
process of Austrian law, and their future success was based on this theft.
Kingslake, pp. 35 - 38.  As Voigtlander is now but a brand name, I suppose
the demanding of recompense by Petzval's heirs would be meaningless.  And,
in any event, the patent Dr Petzval held expired in 1860.

The effect of weathering on light transmission has not been credited to
Fraunhofer but to H Dennis Taylor.  The story is too long to be told here,
but it worked through successive stages to the development of a coating
TECHNIQUE by Smakula, based upon Bauer's work (funded by Zeiss and Pohl).
A similar process was independently developed immediately thereafter by
Kodak and Wollensak, and Zeiss never once considered suing, as these were
independent developments, not thefts.  Again, the PRINCIPLE that lens
coatings reduce flare cannot be patented:  the MANNER in which the coating
is applied, and the chemical composition of the coating, can be.

Finally, if you believe Zeiss Ikon infringed on Leitz' patents with the
Contax RF camera, I suggest you actually HOLD an early Leica and a Contax
I, and learn to use them.  They are quite different.  Yes, both have
focal-plane shutters, but that is pretty much their only similarities.  And
the focal-plane shutter long predates the Leica camera:  the Zeiss-owned
ICA concern was cheerfully manufacturing scads of Palmos cameras in the
first decade of this century, when Barnack was yet a Zeiss employee.

Marc

msmall@roanoke.infi.net  FAX:  +540/343-7315
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