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Pentax Spotmatic

Asahi Pentax Spotmatic
Spotmatic-4.jpg
Overview
Maker Asahi Optical Co
Type SLR
Lens
Lens mount M42 screw mount
Sensor/Medium
Image sensor type film
Image sensor size 24 x 36 mm
Film format 35 mm
ASA/ISO range 20 - 1600
Film speed detection No
Focusing
Focus Manual focus
Exposure/Metering
Exposure Manual exposure
Exposure metering Average, through the lens (TTL)
Flash
Flash FP or X
Flash synchronization 1/60
Shutter
Shutter Mechanical
Shutter speed range 1000 - 1 , B
Viewfinder
Viewfinder pentaprism eye-level viewfinder with a microprism focusing screen
General
Battery Mallory RM640, but 1.5 V silver oxide batteries can be used
Made in Japan
Released 1964

The Pentax Spotmatic refers to a family of 35mm single-lens reflex cameras manufactured by the Asahi Optical Co. Ltd., later known as Pentax Corporation, between 1964 and 1976.

All Pentax Spotmatics used the M42 screw-thread lens mount which was developed before WW2 by Zeiss and Praktica. Asahi Optical used the name Takumar for their lenses. These were high-quality, progressively improved lenses, later versions of which featured multi-coating and were called Super Multi Coated Takumars.

The cameras allowed to focus the lens at maximum aperture to give a bright viewfinder image, then a switch at the side stops the lens down and switches on the metering which can be determined by a needle located on the side of the viewfinder. The use of stop-down light metering was at the time revolutionary, however it limited the capability of the lightmeter specially on low light situations. Later models Spotmatic F, Electro Spotmatic, ES, and ESII were capable of open-aperture metering when used with Super Multi Coated (S-M-C) Takumar lenses with an aperture coupling prong in the lens mount.

Honeywell was the U.S. importer of the Spotmatic. Cameras officially imported by Honeywell were labeled Honeywell Pentax, instead of Asahi Pentax. The Spotmatic IIa was only available as a Honeywell Pentax; it was sold exclusively in the USA and had an electronic interface for specific Honeywell Strobonar electronic flash units.

The original 1964 Spotmatic was one of the first SLRs on the market to offer a through-the-lens (TTL) exposure metering system. The camera was presented as a prototype at photokina 1960, and was originally designed to use spot metering. Shortly before production Asahi decided that spot metering would be too difficult to use, and so the metering system was altered to use center-weighted average metering. The change took place too close to production to change the name, and so Spotmatic stuck. The camera had a mechanical shutter with speed range from 1000 to 1 and Bulb. The lightmeter is activated by a lever on the side of the camera, which also stopped down the lens. Mercury battery (1.35 V Mallory RM640) was used to power the light metering system; however due to the way the circuit is designed, silver oxide batteries can be used instead.


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Wikipedia

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