Re: [Leica] Lens Names

[Nick Hunter <nhunter1@mindspring.com>]

From Marc's post:

>This is the special case which proves the rule.  The Elmar began life as an
>f/4.5 lens, then moved to f/3.5.  By 1940, it had standardized on f/4, with
>the 50mm f/3.5 being the exception.  This lens was subsequently opened to
>f/2.8, oestensibly at Eisenstadt's request.


Didn't the Elmar begin life in 1925 as an f/3.5 lens?

George Huczek had asked:

> Are these names arbitrary, like the 5-letter codes for
>various parts, or do they actually MEAN something?

As I understand it, the earlier Leica lens names were used to refer to
classes of optical design. Before the advent of computers, lens design was
too time consuming to start a unique project for every one; also without
coated lenses engineers had to make do with fewer elements which limited
their options. For this reason most lenses were adaptations, if not
outright copies of earlier designs. Makers gave the lenses of a particular
style the same name so that photographers could get an idea of their
characteristics and uses.

For example, Zeiss used names like Tessar, Sonnar and Planar to describe
"families" of similarly designed lenses. Elmar was the leitz designation
for the very common Tessar-type lens, variously f/2.8 to 4.5, as has been
noted. The Elmar is a triplet with a split rear element. Hektors were
triplets with additional split groups or with the split element in the
central, negative position.

Lenses beginning with "Summ.." were Gauss, or modified symmetric lenses,
typically faster than Elmars, because of the nature of this design. They
might be f/2 (Summar, Summitar, Summicron) f/2.8 (Summaron) or 1.5
(Summarit, Summarex). Super Angulon and Xenon were Schneider names used
because of patents on those lenses.

By the end of the 1950's, lens coatings allowed more elements and
complexity to be used, and the advent of computer design made it possible
to make each lens a  unique solution to its particular purpose. Most
manufacturers dropped the naming of lens types. It lives on in the view
camera world, where categorization by coverage is useful, and a few other
examples, such as Zeiss/Hasselblad and Leica. Leica now uses Summilux to
mean f/1.4, Summicron to mean f/2.0, and Elmarit for 2.8, as has been noted
previously. The Elmar 50/2.8 seems to be the exception, presumably because
of its close connection in design and style to its 1950's predecessor. The
65/3.5 was an Elmar, too (same formula).

The preceding dissertation was intended to save the time and fingers of
Marc, Alf, Patrick, et al, who know far more than I, but whose time should
be saved for more esoteric matters. They will let me know about any errors,
I am sure.

Then again, I visualize dozens of posts being prepared all over the world
with the same info, all uplinked at he same moment! Oh well, another 100
message day on the LUG!

Nick Hunter