Yes, the Kodak Ektar Heliar type lenses are among the best lenses made at
the time. They also were very appreciated for the earlier Hasselblad
cameras like the 1600F and 1000F (80mm and 135mm Ektar lenses); the 80mm
Ektar was clearly better than the Hasselblad 80mm Tessar according several
tests.
I guess the f4,5/10,5cm (105mm) Heliar on the 6,5x9cm Voigtländer Bergheil
made about 1929/1930 is according to Dr.Carl August Hans Harting 1902
second design, because the 1903 third Heliar Harting's design modification
was called "Dynar" and it was f6 to avoid a direct competition with the
f4,5 Heliar, a Voigtländer commercial success; this "Dynar" was re-designed
again in 1925 and it became the f3,5 Heliar, but they still continued the
f4,5 Heliar production according the 1902 second design.
Carlos
2015-09-17 1:50 GMT-03:00 `Richard Knoppow <dickburk@xxxxxxxxxxxxx>:
I am sure you know the history of the Heliar. One interesting
variation is covered in a patent by Fred Altman of Kodak, USP No. 2279384
Altman states his objective (no pun intended) was to reduce astigmatism and
zonal spherical aberration. Included are several references to the patents
for prior art. Kodak exploited this patent for its Ektar 50mm and 75mm
enlarging lenses and a number of camera lenses including some lenses for
the Kodak Ektra camera, the lens for the Kodak Medalist, and the 105mm,
f/3.7 Ektar for small press cameras. Some of these were among the first
coated lenses available. They have a reputation for being exceptionally
sharp. The Ektar series lenses were exceptionally well color corrected,
especially for lateral color, and were meant to encourage the use of color
film. The large format Kodak Commercial Ektar is very nearly apochromatic.
I think the Voigtlander Apo Lanthar is also a Heliar variation using rare
earth glass for one or more elements. Actually, Kodak pioneered in the
manufacture and use of rare earth glasses using lanthanum glass in a number
of lenses. Note that thorium was also used in some glass but is
radio-active enough to cause the glass to turn brown with time. Lanthanum
is not radio-active but many lenses used a combination of the two.
--
Richard Knoppowdickburk@xxxxxxxxxxxxx
WB6KBL
