From these cutaway images, you can clearly see the difference in three
of the lens designs Kodak used. All of these lenses show their origins
in the triplet design that was popular in the early part of the 20th century.
- The first lens is an example
of most Kodak normal length upscale consumer lenses and characteristic
of many professional lenses--a Tessar design--four elements in three
groups, although in this case Kodak designers reversed the last two
elements, putting the positive element next to the stop. For a more
traditional treatment of the Tessar design, see, for example, the design
for the successor to the Kodak 35, the 44mm, f /3.5 Ektar for
the Kodak Signet
. Kodak called these lenses Anastigmat Specials (later Anastars) and
Ektars. Both the first and second lenses above are front cell focusing;
only the front cell is moved, while the remainder of the elements remain
static. This is arguably not the best design, but it reduced production
costs on non-rangefinder models. The success was in the details, since
modern users find that such lenses on Kodak "folders" perform
very well given their modest origins. The Tessar-design lenses used
on professional cameras were unit focusing--all elements were mounted
in a permanent relationship to each other and the entire collection
is moved during focusing. The most common use of these professional
lenses was in press cameras like the Speed Graphic and large single
lens reflex designs, like the Graflex, both of which had moveable front
standards on which the lens could be mounted. The Graphics had coupled
rangefinders and the Graflex had direct focusing through a reflex mirror.
- The second Anastar shown above
was an unusual design for Kodak and followed an earlier design used
on the German Ernostar and Sonnar lenses--four air-spaced elements.
This design uses an additional second element that raises the maximum
aperture of the triplet design.
- The third lens above is also
an unusual design for Kodak using five elements in three groups--a Heliar
design, a specialty of Kodak designer Fred Altman--shown here as used
in the Kodak Medalist. Kodak also used this Heliar design for a 105mm
f/3.7 for small press cameras and as a 35mm 31° design as a wide
angle lens for the Kodak Ektra. Five elements made this an expensive
lens for the Kodak, but you might say that Kodak was an early adopter
of the prosumer marketing strategy.