Lens design & glass types

[IanG]

Around 1931 when Compur redesigned their shutters from Dial-set to Rim-set the glass in some lens designs appear to change is this true ? (This also co-incides roughly with the introduction of more specialist glasses that allow the manufacture of the faster lenses such as the Summar f2).

I have a number of Tessar's 135mm /150mm and the glass in the pre 1931 models seems quite different to the later versions. The lenses seem to have been re-designed, the newer glass is softer more prone to scratching, cloudiness etc.

Ian

[Ole Tjugen]

The Zeiss Tessar was continuously redesigned throughout its century-long production time. So were most other lenses, and the new and improved glasses around 1930 led to many "tweaks" around that time. Just like the introduction of the first special glasses in the 1890's made the anastigmats possible in the first place.

[Dan Fromm]

Um, Ole, a while ago in a discussion about f/6.3 CZJ Tessars, Arne Croell told me that the lens' first redesign was in 1912 to improve ease of manufacture, not performance, and its second after the war. The faster Tessars may well have been redesigned more often, but I'm not sure it is safe to generalize about how often or rapidly designers took advantages of new glasses to improve old designs.

Happy new year,

Dan

[Ole Tjugen]

The f:4.5 Tessar in particular is a difficult lens to improve - attempting that is classical exercise in various optics design software packages. :)

[IanG]

Dan, I'm after finding any information on this apparent re-design in the early 30's. The glass type appears to change, the cell sizes differ etc.

It's well known that the design of the Tessar changed after WWII because of the unavailability or shortages of some specialist optical glasses.

Ian

[Dan Fromm]

Ian, I can't predict when Arne Croell will look in here and notice this thread. PM him, he has all of Hartmut Thiele's books on Zeiss products and production.

FWIW, I have in hand 1912 and 1936 150/6.3 CZJ Tessars and they're the same lens.

[BrianShaw]

Around 1931 when Compur redesigned their shutters from Dial-set to Rim-set ...

Was it that late? I recall reading (somewhere) that dial-set Compur was last manufactured in 1925. Maybe my recollection is faulty.

[CCHarrison]

FROM: 100 Years of Carl Zeiss Tessar®

Exactly 100 years ago, Carl Zeiss was granted a patent for an invention
which became the most famous camera lens of all times:
the Tessar® lens. Until the death of Carl Zeiss,
the company’s founder, in 1888,
the firm almost exclusively manufactured
microscopes with one exception:
the Abbe refractometer.
In the early days of the company's
history, outstanding developments
were made by Ernst Abbe
who was first a scientific colleague,
then a partner and finally
the founder of the Carl Zeiss
Foundation, thus increasingly determining
the fortunes of the
company. Ernst Abbe was not
only a scientist, but also an entrepreneur.
Currency crises occurring
around 1893 negatively affected
the export of microscopes which
induced Abbe to think about
extending the product line, thus
reducing the company’s dependence
on only one product. From
1888, Ernst Abbe started to diversify
the product line. Camera lenses
became a new business division.
However, Ernst Abbe also
granted licenses to companies
outside Zeiss. This procedure
avoided an abrupt growth of the
new division at the expense of
the other divisions. He deliberately
accepted the disclosure of development
and manufacturing
know-how to competitors.
A few highly talented scientists
which he had employed played a
major role in making this strategy a
success. Paul Rudolph was one of
these scientists. He is the father of
some camera lenses which are still
produced to this very day. He created
the Anastigmat camera lens which
was produced from 1890 and renamed
Protar® in 1900. Paul Rudolph
designed two further lenses during
this period, the Planar® lens – produced
from 1896 – and the Tessar®
lens which has been produced since
1902. The name Tessar gives a clear
indication of the structure of the lens:
“tessares”, Greek for “four”, indicates
that the lens consists of four
lens elements.
What is the outstanding feature of
Tessar®? In the early days of photography,
pictures were taken in black
and white. Glass plates were the “image
storage media” used by serious
photographers. The light sensitivity of
the emulsions used was so low that
shutter speed was counted in minutes.
The preferred lenses at this time
were two-element systems with a low
speed and rather modest image quality.
A few high-speed lenses existed
with an aperture of about f/3.5 which
cost more than a saddle-horse, provided
pictures smaller than a postcard,
and whose definition was limited
to the center of the image.
Paul Rudolph used new types of
optical glass provided by the Jenaer
Glaswerk Schott & Genossen: for example,
glass types with finer grading
of the refractive indices at a given color
dispersion. The use of these types
of glass made it possible to achieve excellent
color correction, including the
correction of astigmatism, spherical
aberration and field curvature in the
Planar® lens. However, the lenses were
large and heavy. As anti-reflective technology
was still unknown at this time,
the pictures also lacked brilliance.
Paul Rudolph found an ingenious
solution to solve some of the prob-
100 Years of Carl Zeiss Tessar®
32 Innovation 11, Carl Zeiss, 2002
Anniversaries
Fig. 1:
Dr. Paul Rudolph
the inventor of the
Tessar® lens
Fig. 3:
4.5 x 6 Sonnet with a 7.5 cm
Tessar® f/6.3 lens
Contessa Nettel , Stuttgart,
1921
Fig. 2:
Cutaway of a Tessar® and
30 cm Tessar f/4.5 lens for
Ica 13 x 18 cm reflex camera 2
lems. The Tessar® lens belonging to the
type of “Triplet lens” was created. The
design using a dispersive element
placed between two collective elements
results in anastigmatic imaging.
Instead of individual elements, it is
also possible to use cemented components.
In this case, the image-side
component consists of a dispersive
and a collective element. The lens with
its initial aperture – “speed” – of f/6.3
was patented in 1902. The redesign
performed by Ernst Wandersleb in
1904 resulted in the Tessar® f/4.5 lens
which was available from 1907.
Innovation 11, Carl Zeiss, 2002 33
This was soon followed by an f/3.5
version for cinematography and projection.
In 1908/1909, Ernst Wandersleb
designed the precursor to the
convertible lens sets of the Tessar®
lens with an exchangeable front element.
Willy Merté’s development resulted
in the Tessar® f/2.8. lens in
1932. A year later, the Tele-Tessar®K
lens (f/6.3/180 mm) with its sensationally
high speed was introduced for
the Contax® camera built from 1932.
A “quantum leap“ in the image contrast
provided by optical systems resulted
from the “anti-reflective coating“ invented
by Alexander Smakula at Carl Zeiss,
a thin, reflection-reducing, vacuumdeposited
layer. A patent application
for this procedure was filed in 1935.
The Tessar lens was launched on to
the market in many versions. Highquality
stereo lens pairs were part of
the Carl Zeiss product spectrum at an
early stage. For example, Paul Franke
and Reinhold Heidecke used precisely
paired 55 mm Tessar f/4.5 lenses in their
first Heidoscop stereo camera as early
as 1920, the year when they founded
their company which was later to
achieve world renown as “Rollei-
Werke Franke & Heidecke”. Worth
mentioning is also the 500 mm I.R. –
Tessar® f/5 lens for aerial photography
in the 30 x 30 cm format. An interesting
design created in 1951, the Zeiss-
Ikon Panflex® mirror box, combined
with the 115 mm Panflex-Tessar®f/3.5
lens launched in 1953, made it possible
to use the Contax® viewfinder
camera like a reflex camera.
Standard lenses like the current
45 mm Tessar® T* f/2.8 lens for the
Contax reflex camera are generally
achromats featuring correction of
chromatic longitudinal aberration for
two wavelengths. This also applies to
the Tele-Tessar® lenses which became
available for the 35 mm and the 6 x 6
cm formats from 1968. The modern
lenses of the Tele-Tessar® T* type for
the Contax® and Hasselblad Series
200 cameras are also achromats. The
Tele-Tessar® HFT lens is available for
the Rolleiflex System 6000. T* and
HFT stand for enhanced transmission
thanks to multilayer coating.
Higher demands made on color
correction are met by apochromatic
lenses which are corrected for three
wavelengths. As early as 1923, the
Apo-Tessar® lens was the most often
used lens in reproduction photography.
From 1982, a 500 mm Tele-
Apotessar® f/8 lens was provided for
the Hasselblad 550C camera. There
are now different versions of the Tele-
Apotessar® T* lens for cameras such
as Contax®, Contax® 645 Autofocus
from Yashica and cameras from
Hasselblad and Rollei.
The image definition and brilliance
provided by the Tessar® lens resulted in
the slogan “the eagle eye of your
camera” in 1931. The image-side cemented
component was the original
from which the “lens logo” was derived
and used for many decades as a
trademark of the company. To this day,
Carl Zeiss has produced about 5 million
Tessar® lenses for image sizes mea-
Fig. 4:
Contax® Aria with a 45 mm
Tessar f/2.8 lens
“Star of Vision Award”
Ahead of the biggest ophthalmic
exhibition in the USA, the “Vision
Expo East Award”, pioneering
achievements in the optical industry
are awarded prizes. In 2002, the
panel of specialists presented the Star
of Vision Award to Carl Zeiss, for
a trail-blazing invention made in
1935: the anti-reflective coating of
optical surfaces developed by
Prof. Alexander Smakula. Since then,
the anti-reflective coating has also
improved the results obtained with
the Tessar lens as is illustrated by the
two historic photos taken with and
without AR coating. It is not unusual
for pioneering inventions to remain in
use for a long time, but it is certainly
not an everyday occurrence for them
to be honored with an award many
decades after they have been made.
suring from half a fingernail to the
door of a room. All over the world,
lenses are produced which are based
on the Tessar® design, some licensed
by Carl Zeiss. The result: more than
150 million units sold to this day.
Note:
Tessar® is a registered
trademark
Dr. Wolfgang Pfeiffer, Aalen
Kornelius Fleischer, Camera Lens Marketing
k.fleischer@zeiss.de
Dr. Dieter Brocksch, Corporate Communications/
Technical Information
brocksch@zeiss.de

[Arne Croell]

Ian, I can't predict when Arne Croell will look in here and notice this thread. PM him, he has all of Hartmut Thiele's books on Zeiss products and production.

FWIW, I have in hand 1912 and 1936 150/6.3 CZJ Tessars and they're the same lens.
Well, I saw it pretty late, Dan. Anyway, for most of the f/4.5 versions there was a major redesign in 1927-1929, according to the lists in Thieles book. The 13.5cm one was redesigned 1927 and all lenses manufactured after 1928 used that design; however, the redesign of the 15cm from 1928 did not see production until the 1950's and was still made according to the 1911 design before and during the war. All the longer focal length (18, 21, ...50cm) were redesigned in 1928-29 and mostly manufactured according to that design, but the manufacturing lists occasionally show batches with the old designs in between. Its not absolutely straightforward.

[IanG]

Well, I saw it pretty late, Dan. Anyway, for most of the f/4.5 versions there was a major redesign in 1927-1929, according to the lists in Thieles book. The 13.5cm one was redesigned 1927 and all lenses manufactured after 1928 used that design; however, the redesign of the 15cm from 1928 did not see production until the 1950's and was still made according to the 1911 design before and during the war. All the longer focal length (18, 21, ...50cm) were redesigned in 1928-29 and mostly manufactured according to that design, but the manufacturing lists occasionally show batches with the old designs in between. Its not absolutely straightforward.

Thanks Arne.

For some reason I didn't see your reply until I did a search today. What you've said coincides with what I've observed with my 135mm tessar's.

The design change must be connected to perhaps triggered by the switch from the dial-set Compur to the new rim-set Compur shutters, but it also seems to be using new types of optical glass.

I also have a 50's CZ Jena150mm f4.5 Tessar and that's quite different again, both arms of Zeiss had been co-operating closely at that point, despite different nominal ownership they had high hopes of re-joining the disparate halves.

Post war East German Tessar's (particularly for Rollei's) seem to have a poor reputation usually blamed on slack quality control, but there was no consistent supply of specialist optical glasses and it appears the lens was re-designed on the fly to use whatever specialist glass was available. This is an area that needs researching.

Back to the point my pre-1928 Tessar's are better lenses compared to my 30's Zeiss lenses, that may well be due to ageing, but my 30's Tessars and Novar are less contrasty than the older Zeiss lenes & far more prone to flare despite being in excellent condition.

Ian

[Dan Fromm]

Ian, it depends on the Tessar. My 1912 and, IIRC, 1936, 150/6.3s seem to be identical, details of mounting excepted. Both are in barrel. Arne and I discussed when the f/6.3s were redesigned, IIRC the design dates were 1903, 1911 (to improve ease of manufacture), and sometime post WWII for some but not all focal lengths. The original f/6.3 Tessar seems to have been right from the start, so very hard to improve.

There've been comments in this thread about redesigns due to availability (or not) of glasses. Maybe. Eric Beltrando once told me that the glasses that Boyer bought weren't exactly the same from batch to batch and that each design was tweaked lightly to suit the refractive index and dispersion of the new batches. He didn't see these as redesigns, rather as adaptation to variability in the materials used.

[Paul Fitzgerald]

" Worth
mentioning is also the 500 mm I.R. –
Tessar® f/5 lens for aerial photography
in the 30 x 30 cm format. "

What does the I.R. refer to? Infra-red maybe??

[IanG]

Dan, it would be interesting to know the break-down of Tessar production at Zeiss during the inter War years. I suspect that the 135mm outsold the 150mm in Europe as the 135's are much more common on 9x12 cameras. But I'd guess that sort of information is long lost.

That would then lead one to speculate if the 1928 re-design was to get improved coverage making use of the new optical glasses which had just become available.


Eric Beltrando once told me that the glasses that Boyer bought weren't exactly the same from batch to batch and that each design was tweaked lightly to suit the refractive index and dispersion of the new batches. He didn't see these as redesigns, rather as adaptation to variability in the materials used.

Those are names I haven't seen mentioned before, I'll have to remember where I read about the glass problem, I will have saved it somewhere.

ian

[Archphoto]

Paul, yes it could be that this lens was specialy made for IR photography and corrected for it.

Peter

[Dan Fromm]

Ian, see http://www.galerie-photo.com/boyer-optique-objectif.html and www.dioptrique.info

[Archphoto]

Thanks for posting these links, Dan, they are great.
Esp the last one gives a lot of insight into the development of photographic lenses.

Peter

[Paul Fitzgerald]

"Paul, yes it could be that this lens was specialy made for IR photography and corrected for it."

Thank you Peter, now I'll have to find some IR film and see if there is a difference in the focus spread.

For general reference, with a slight trim to the flange the 500/5 does fit onto a 6x6" lens board and mounts flush with the rear surface so it works with the built-in Packard shutter.

[Lynn Jones]

Thanks to CC Harrison,

I joined the original Calumet in 1964. We became the largest selling large format camera maker in the world (by 1967, 85% or a bit more of the VC cameras in the world). Quality lenses was our problem, American made Goerz had changed ownership 3 times and the quality was extremely variable. Schneider Symmars had some contrast problems and the shutters had sereious problems. One out of ever 5 lenses were failing at that time. Commercial Ektars, Wide Field Ektars and the portrait soft focus lenses sold well and stayed sold.

We received a message from Kodak that the professional lens division would be shut down in 1965. We bought lots of the warehouse stock and started looking for a new source. About this time a friend with a small investment group bought Ilex Optical. The president, our friend Manny Kiner agreed to make lenses for us with our name, Caltar. Manny studied the Commercial Ektar (tessars) and found that with some new optical glasses and computer re-design, we could make f 6.3 tessar type lenses of quality superior to Commercial Ektars. Within a year we were making and selling as many of our lenses as Schneider from our catalogs. Manny created a Super Wide 103 degree 90mm lens (Wide Field Caltar) which we put into Seikosha shutters followed by a 72 degree single convertible plasmat which we called the S Caltar. The S Caltar attracted so much attention that Rodenstock made a super deal for private labeling that particualr lens, although the 215mm f4.8 S. Caltar continued to be made for several more yers.

Manny had a terrible auto accident with such brain damage that he could no longer design lenses or work. Ilex over a period of 25 or so years eventually failed, but in the meantime B&J and BBOI made the same Ilex lenses under their own name as did Ilex as the original "Paragon" name. However, from the 1960's 'til the 1980's these lenses sold a huge percentage of LF lense under 4 different trade names.

The Calumet 4x5's (3 different models, one of which I created) and the 8x10's during the peak of production sold 12,500 to 13,000 cameras per year, internationally. The rest of the market was under 2,000 units.

Lynn

[Emmanuel BIGLER]

Ian, see ...

Daniel W. Fromm is so fluent in French that he forgot to mention the original English version of his invaluable article on Boyer lenses:
http://www.galerie-photo.com/boyer-lens-optic.html
"Traduttore, traditore !" Best to refer to the Urtext !

[IanG]

Thanks Emmanuel.

Ian

[Mark Sampson]

Wow. Lynn, thanks for the history. I don't think that story is well known, and I live in Rochester; at one time, most of the photos I made my living with were Kodaks and one very nice Ilex-Caltar.
Have you considered writing down the whole story for this site? There are many LF lens/optics aficionados here who would love to hear it.

[Jan Pedersen]

Lynn, Thanks for this, I for one would like to get the full story, so far i have 6 Ilex Calumet Caltar lenses and find them all to perform very well. The 508/7 being the most interesting of them since it is very close to mint.