"Nihon size" or "Nippon Format"
According to Dominique and Jean-Paul Francesch in their study "Histoire de
L'Appareil Photographique Minolta de 1929 à 1985" Minolta was the first company, in 1947, to introduce
the 24x32mm image format in a 35mm camera. This image size, virtually unique to Japan came to be know as the Nihon size"
or "Nippon Format".
In fact, the accepted opinion that the 24x36mm image format was the standard negative size, established
by the Leica, and universally accepted by Contax, Kodak, et. al. is not totally correct. Leitz first adopted a negative
size of two frames of movie or cine film with an image size of 24x34mm. Upon the commercial introduction of the standard
Leica camera, this size was increased to the now standard 24x36mm image format, also used by Contax, Kodak, Voigtlander
during the 1930s.
Also, the 24x32mm "Nihon size" or "Nippon Format" was not unique to the Minolta-35,
and was in fact used in a number of 35mm Japanese designs in 1948. It is often forgotten that the first Nikon
rangefinder, the Nikon I of 1948 used this format. Also, the first
Olympus 35mm format camera, the rangefinder Olympus 35 I of 1948 as well as the Minion 35 of 1949 employed
this format. The Minion's exposure counter went to 44, because the smaller images allowed at least 40 images per
roll of 35mm film. Olympus within one year decided to replace the Nihon format by the 24mmx36mm format which they
used exclusively after 1949.
Nikon in its historic site refenced below gives further reasons for this negative size:
"...The reasons to adopt the 24 x 32 mm format were:
The 3:4 proportion seemed to have better proportions than the "Leica" format (2:3).
It could take 40 frames and was more economical than the "Leica" format of 36 frames.
The standard of the slide projector provided by the Japanese Ministry of Education was 24 x 32 mm.
It was decided according to the basic idea of adopting our original picture size, which differed from that of the "Leica"...."
This is the version set forth in the Nikon historic site (internet link shown below).
A couple of mistaken impressions about the 24x32mm
format: some sources refer to this image ratio (3:4) as being the "golden mean" (from Pythagoras). That is incorrect,
since the golden mean ratio is 1:1.618. Another claim was that it was a consequence of the usual office paper size,
but the A series of paper sizes (used in Japan then and now) are 1:1.4142, since for all sizes, the height
divided by the width equals the square root of 2.
However, if not linked to office paper size, the
24x32mm image format is more practical for enlargement on photographic paper for enlargements, which is often a multiple of
3 x 4. It is also interesting that there is now an industry movement to standardize on 3 x 4 as the format for image
sensors for digital cameras. Perhaps this 1947 format will make a big come-back in the Twenty-first Century!
Nikosan, in his interesting site referenced
below, says that the "Nihon" negative size was banned by the "GHQ" (presumably Gen. MacArthurs' HQ), and Minolta then modified
the Minolta-35 C to the 24x33mm format. (Nikon at that time moved to the 24x34mm format, used in the
Nikon M and Nikon S cameras.)
Others have said the Occupation Authority would not
allow this negative format to be exported, but in 1947 and until perhaps about 1952, almost no Japanese 35mm cameras were
exported. Minolta's first foreign subsidiary (in the US) was formed in 1950, and Canon US exports were primarily
through US Post Exchange purchases in Japanese military bases.
Perhaps the US Post Exchange stores in Japan would
not accept the format. In any case, by the early 1950s, all Japanese manufacturers seem to have abandoned the 24x32mm
format, although Minolta did not adopt the full 24x36mm format for the Minolta-35 until 1958.
Another explanation that I have read is that the US had import duties on cameras with language
intended to favor European 35mm cameras, versus Japanese 35mm cameras. This explanation claims that the duty specification
referred to cameras having a 24mm X 36mm image size. According to this story, the Japanese manufacturers adopted
the smaller image size to circumvent the prohibitive US import duties by avoiding the definition. I doubt
this version, since in spite of research, I have not located such a US import duty from that era. Also, considering
the logic of this story, why would the US seek to favor the recently defeated Germany versus the recently defeated Japan,
both occupied by US forces, and both of which needed to restore their industries.
However, there is another version, centered on Minolta and described in "Histoire de L'Appareil
Photographique Minolta de 1929 à 1985" by Dominique & Jean-Paul Francesch. They say, regarding this
format: "However, the Minolta-35 possessed for the first time in the history of cameras a feature that was not unimportant;
the 24x32 mm format. It was the chief designer of Minolta, Hajime Miyabe, who perfected the new format, judged by him,
and correctly so, more logical than 24x36 mm. Indeed, the corresponding proportions of 24x32 mm is very close to those of
the paper formats used for enlargements. The ratio of 24x32 is 1.333 whereas the ratio of 24x36 is 1.50; if the one
compares these two ratios with the paper size usually employed in the developing laboratory, the excellent match is obvious."
This version credits the "Nippon Format" to the invention of Minolta.
Of all the "explanations" of the demise of the "Nihon format", most convincing to me is that
the Kodak Kodachrome processing of color transparencies and mounting them into cardboard 35mm slides required the standard
24mmx36mm image size and spacing to function properly.
Minolta was the slowest to abandon the Nihon format.
Negative sizes of the Minolta-35 gradually increased from 1947 as shown in the Minolta-35 table (click link below), but it
was not until the introduction of the Minolta-35 II B in 1958 that the Minolta-35 adoped the now standard 24x36mm