The Mamiya Camera Co. Ltd. was established in 1940 to produce twin lens reflex cameras using medium format roll film. The range of interchangeable lens Mamiyaflexes was highly successful. The company got into the 35mm SLR market at about at the same time as most of the reputable Japanese manufacturers did in 1959. Their first family however was not a very ambitious one, despite using the Exakta bayonet lens mount. This was the low cost range of Mamiya Prismats. Then, in 1963, a rethought model was launched, using the at the time quite popular, but soon obsolete 42mm Praktica screw mount. This was the Mamiya/Sekor.

The Mamiya/Sekor CWP or sometimes, just Mamiya/Sekor, was the first screw lensmount 35mm SLR camera from Mamiya Camera Co. Ltd. It was launched in 1964, the same year as the quite similar Canon FX, but two years after the Minolta SR-7. It stayed on the market for two years. It has a built-in exposure meter with the CdS cell positioned just in front of the wind-on lever. A High - Low meter range switch is situated coaxially under the shutter speed dial, on which the film speed is set lifting and turning it using a scale on the perimeter. The meter read-out window is next to the rewind knob, showing F-values to be transferred to the lend aperture ring. The camera has neat design, but a slightly rough and heavy feel. The focusing screen has a micro prism centre spot, surrounded by a ground collar and Fresnel rings. The finder has a 19mm (¾") thread for accessories. An automatic frame counter is visible under a window in front of the wind lever. The standard lens is the Mamiya/Sekor 1:1.8 f=55mm in black with a 52mm chrome filter ring, and an M - A slide aperture selector switch.

The CWP body has some are slightly out of the ordinary features; the self-timer at the front has a release button in the wind lever hub. The missing meter switch is already mentioned, draining at all times the 1.35volt mercury cell sitting in its base compartment; covering the cell minimises the drain. The rewind button is raised to disengage the film cassette, but the back door has a latch at the side. The tripod socket is moved forward on a base plate protrusion not found on many SLR cameras. The strap eyelets are stamped out, possibly of stainless steel. However, TTL metering was taking over, and the much improved model 1000DTL, based on the CWP, followed.

Mamiya/Sekor 1000 DTL[]

The Mamiya/Sekor 1000 DTL replaced the CWP in 1968. It was the first 35mm SLR with spot and average exposure metering, selectable pushing a small switch to either setting on the lover left-hand side of the mirror housing. A bracket within the finder image area indicates the spot area, and a black triangle points to either an S or A. The spot-metering cell is behind a semi-silvered area on the mirror. A meter pointer moves along the right side in the frame in response to the light level and exposure parameters. An inverse C acts as the centre mark, with over and under exposure indicated by signs above and below.

The camera body is quite similar to the CWP, but with some restyling, but the back door latch is still separate from the rewind knob. The new cross head screws fastens the covers. The finder frame is square and accepts accessories, like a sturdy flash shoe with a retainer clamp. The DIN/ASA dial is improved, but still incorporated into the shutter speed dial. The 1000 DTL is an early user of the 1.5volt EPX76 battery.

The controls on the 1000DTL are quite original, and rather clever. The camera utilises the stop-down exposure metering. However, instead of an awkward slide switch, the wind-on lever doubles as the meter control: The meter is switched on by moving the lever slightly out from the body. It stays in this position until the wind lever hub button is pushed, where-upon the lever slips back to rest, and the meter circuit is off. The clever trick, however is pushing the lever back, while in the stand-off position, closes the lens aperture to its preset value, enabling stop-down meter reading while observing the meter indicator in the finder. It is quick and easy as long as one is using the right eye looking through the finder.

The standard lens is the all black Auto Mamiya/Sekor 1:1.8 f=55mm with a 52mm filter ring and an M - A slide aperture selector switch.