The Minolta-35, Chiyoda Kogaku's first 35mm camera was introduced in
1947 with the now famous 45mm f2.8 Super Rokkor LTM lens. This 45mm f2.8 lens was standard on the Minolta-35 for
the next 8 years. It was marked with Minolta's "Rokkor" lens name as well as "Chiyoko", a phonetic contraction of
Chiyoda Kogaku". "Rokkor" refers to the Rokkor or
Rokko mountains near the Osaka (Mukogawa factory) manufacturing location.
Minolta-35 Lens Mount:
Unlike the leading Japanese rangefinder camera at that time (Canon),
the Minolta lens mount was an exact copy of the Leica 39mm diameter mount, with a standard 1mm screw pitch,
referred to by some as the "universal" mount. (Canon's evolution of lens mounts is described in the link, below.)
The Rokkor lens selection for the Minolta-35 was somewhat limited when compared
with other leading 35mm rangefinder ranges of the period. For example, as far as is known from present research, no
lens wider that 28mm was offered. Also, fast lens formulations of f2.0 were not generally offered. Even a fast
50mm formulation of f2.0 or f1.8 was not offered until 1955.
However, one innovation was with the 35mm f3.5 lens, which was the first lens
manufactured in Japan with multi-coating achromatic lens coating, introduced in 1956. Minolta in its historical site
claims the first multi-coated achromatic lense coating in the world for its twin lens reflex cameras of the early 1950's, The
35mm f3.5 with achromatic coating apparently did not sell particularly well, since even in 1956, a maximum aperature
of f3.5 was considered slow.
Unusual Characteristics of Rokkor rangefinder lenses:
There were a number of somewhat eccentric decisions
made in the Minolta Rokkor 39mm mount lenses. One area relates to camera lens filter size. Although the Rokkor
85mm f2.8, the Rokkor 110mm f5.6 and the Rokkor 135mm f4.0 use 40mm screw-in filters, the early version of the 50mm f2.0,
the 50mm f2.8 and the 28mm f3.5 Rokkor lenses use 40.5mm filters.
The standard lens supplied with Minolta-35 cameras
from 1947 to about 1955, the 40mm f2.8 used a 34mm filter. Also, the inner ring surrounding the front lens element
of this lens has threading for a 21.5mm filter. Beginning in 1955 with the Model II (b), the 50mm f2.8 with a
40.5 mm filter size began to be routinely offered.
The unusual focal length 110mm f5.6 Tele Rokkor was produced in a chrome body with black head
ring and black f-stop and focusing rings, and also in an all chrome body (apparently rarer than the black/chrome version)
as shown in the illustration below.
The 135mm f4.0 Tele Rokkor was also produced in both black/chrome and all chrome versions,
as shown from the Japanese camera advertisement, below, from the period.
Rokkor SLR lens formulations in LTM:
Not listed in the table below are certain Minolta SLR lenses that were apparently
offered in LTM, but without rangefinder coupling. One such lens, seen occasionally for sale is the Macro Rokkor-QF 50mm