Konishiroku Semi Pearl

The Semi Pearl is a 4.5×6cm folder, released by Konishiroku (the later Konica) in 1938, and succeeded in 1949 by the Pearl (I).

The name "Pearl" was used by Konishiroku for many other models of rollfilm folders. Other articles deal with the early Pearl for plates and rollfilm, the Pearl No.2, the self-erecting 6×9 Pearl, the postwar Pearl (I), II and III and Pearl IV, and the Baby Pearl and Pearlette cameras.

The Semi Pearl is a vertical folder much inspired by the Ikonta A. The three-part folding struts are curved and are engraved with Konishiroku's logo: a five-petal cherry blossom containing the Japanese character 六 (the roku within both "Rokuoh-sha" and "Konishiroku"). The metal parts are chrome plated. The body edges are silver painted on the early examples and black lacquered on later cameras (see below). The name SEMI PEARL is embossed in the leather covering at the front.

There is a folding optical finder at the top, as seen by the photographer holding the camera horizontally. Its rear part is chrome plated and its front part is black. The folding bed release is on the right, easily mistaken for the shutter release; it simultaneously opens the finder. The actual shutter release is on the front door, close to the hinge, and is tripped by the photographer's left hand — a position which was perhaps inspired by Voigtländer's Bessa.

The back is hinged to the left for film loading, and the latch on the right is covered by a short handle. The film is advanced by a key at the bottom right, and its position is manually controlled via red windows.

Most examples have unit-focusing: the lens and shutter assembly is mounted on a focusing helix driven by a small tab running on a distance scale engraved in metres or feet. A few cameras have front-cell focusing instead, presumably because of a shortage of parts.

The shutter of the Semi Pearl is either an Apus (10–100, B, T) or a Durax (1–100, B, T). Both were made by Rokuoh-sha, later Konishiroku. Both have a cocking lever, and none has flash synchronization (on some examples, this feature was added as an aftermarket conversion).

The Semi Pearl normally have an Optor 7.5cm f/4.5 three-element lens or a Hexar 7.5cm f/4.5 four-element lens, but a few have a Hexar Ser.II 7.5cm f/3.8, surely not an original version. The Optor was reputedly manufactured by Asahi Kōgaku (predecessor of Pentax) under license from Konishiroku, but its production was perhaps taken back by Konishiroku at some time.

The Semi Pearl released in 1938 is known as the "silver" Semi Pearl due to its finish. Examples of the silver Semi Pearl are known with the two advertised combinations: Apus and Optor or Durax and Hexar Ser.1. The back has two red windows, placed towards the top and protected by a common slider, a configuration similar to that of contemporary Pearl (6×9cm), Baby Pearl or Luxury Pearlette. The Durax or Apus have the first shutter plate design, marked Rokuoh-sha under the lens. The shutter name is inscribed on a plate attached at the top by two screws, and the aperture scale is engraved on another separate plate at the bottom. The lens is marked Rokuoh-sha too, and usually has a chrome bezel. (The focal length is usually engraved as 7.5cm, but extremely early Optor lenses have 75mm instead). The name SEMI PEARL embossed in the front leather has a rectangular frame. It seems that the earliest examples have a small focusing tab; it was soon replaced by a larger part.

The silver paint on the body edges was replaced by black lacquer at some time, perhaps during the early 1940s. The lens bezel of the Hexar and Optor lenses became black at about the same time, or slightly earlier. These "early black" Semi Pearl still have the Rokuoh-sha markings on the lens and shutter, and have no other change. They are known with the Apus and Optor or Durax and Hexar Ser.1 combinations. Two of these (with Durax and Hexar Ser.1) have been observed with the words ROKUOH–SHA and MADE IN JAPAN embossed on the back leather. This might indicate a postwar origin, but this is unsure.

The adoption of the Konishiroku marking on the shutter brought the second shutter plate design, with different metal stripes on the sides of the lens, of markedly unequal length. The main plate was used for both the Durax and Apus, and the shutter name was added on a separate plate screwed to the top. A single Apus shutter is known so far with a Konishiroku marking; it is mounted on an example with front-cell focusing and still has the old type of aperture scale. On the Durax shutter, the aperture scale screwed to the bottom has a new shape with square ends, looking more modern. It is not known if this second shutter plate design was introduced before or after 1945.

At about the same time, the Rokuoh-sha marking on the Hexar Ser.1 f/4.5 lens was replaced by a Konishiroku marking. The serial number of the Hexar Ser.1 was perhaps simultaneously reset to 30000. These lenses might be the first produced after the war, but this point is again obscure. An example with the second shutter plate design and Konishiroku Hexar Ser.1 f/4.5 lens no.33949 is the earliest known camera with a distance scale in feet, a feature which surely appeared only after 1945, when the US soldiers stationed in Japan were the main customers.

The production of the Semi Pearl was resumed almost immediately after the war's end, perhaps as soon as October 1945. It was at first drawing on stocks of older parts. However the dies and leftover parts found at the factory came in odd sets: for example the number of front and rear lens elements was not matching. At the very beginning, the monthly production rate was very low, about 10 or 20.

The earliest cameras assembled after 1945 were perhaps indistinguishable from the late wartime production, except maybe for the MADE IN JAPAN embossing. The replacement of the focusing helical by front-cell focusing was surely caused by a shortage of parts. The times were tough, and the wartime stocks surely began to ran out before orderly production could start again - the same occurred to other Japanese manufacturers at the same period, see for example the shortage of shutters for the Olympus Six).

All the front-cell focusing Semi Pearl observed so far have a Hexar Ser.1 7.5cm f/4.5 lens. Some have an older lens with chrome bezel and four-digit number, and a Rokuoh-sha Apus shutter; these parts were surely taken from old stocks. The others have a black lens bezel and the second shutter plate design; one has a Konishiroku Apus, and another has a Konishiroku Durax and lens no.311xx.

After this difficult transition period, it seems that the production of the Semi Pearl reached a regular pace. Several cosmetic changes were introduced to the cameras, typical of the "regular postwar" Semi Pearl. A new type of artificial leather covering was adopted, with slightly different markings: the SEMI PEARL embossing at the front leather received a hexagonal instead of a rectangular frame, and the KONISHIROKU embossing on the back was inscribed in smaller letters inside a hexagon, with no MADE IN JAPAN mention. The shutter plate was modified once again, and the third shutter plate design has a direct stamping of the Durax name and aperture scale, replacing the small screwed plates. The Apus shutter was abandoned, and its production was probably not resumed after 1945.

After some time, the lens name "Hexar Ser.1" was simplified to "Hexar" — the transition occurred somewhere in the 35xxx to 38xxx serial range. The introduction of lens coating might have occurred some time afterwards, but this is unconfirmed.

It seems that there was a brief attempt at reviving the production of the Optor f/4.5 lenses, and a few such lenses are found with Konishiroku markings on a black bezel. The license contracts with Asahi Kōgaku were surely invalid by that time, and these new Optor lenses were surely assembled by Konishiroku itself. The serial number was perhaps reset at 1000: at least three such lenses are known with a four-digit number in the 1xxx range (one of them pictured at this site), on cameras with the second or third type of shutter plate. The only other Konishiroku Optor observed so far has no.60267; this might correspond to a very late batch whose numbers were taken on the Hexar sequence, but the details are completely unknown.

The last Semi Pearl have a single red window in the back, near the bottom, protected by a cover horizontally sliding under a metal plate - the back is therefore identical to that of the Pearl I. This version is pictured in the book Semi Pāru no jōzu na tsukaikata by Akiyama Seiji, published in August 1948 — it was thus already in existence by that time.

The Semi Pearl with a single red window are not uncommon today, and were produced for a number of months, certainly until the release of the Pearl I in late 1949 or early 1950. The last known mention of the Semi Pearl is in the December 1949 issue of Photo Art, on Japanese cameras.

Nearly all the examples have the Durax and Hexar f/4.5, and lens numbers are known from 44xxx to 62xxx, in a sequence which is perhaps shared with other Hexar lenses. The only exception confirmed so far is a camera with a Hexar Ser.II f/3.8 lens. Isolated examples of the Semi Pearl are found with a Hexar Ser.II f/3.8 lens. At least three examples have been observed so far. All have Rokuoh-sha markings on a chrome bezel, giving a typical 1930s aspect, but they were surely assembled after 1945.

It seems obvious that the f/3.8 Semi Pearl was not an official version sold by Konishiroku. It is likely that the Hexar Ser.II f/3.8 lenses were made for a different purpose in the late 1930s or early 1940s, perhaps in association with the Compur-Rapid shutter on some military camera. A small stock of these was perhaps discovered after 1945, and mounted on a handful of Semi Pearl bodies. This might have occurred within the Konishiroku factory, perhaps as a private initiative by some worker.

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