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.
Asahi Pentax Spotmatic
Maker Asahi Optical Co
Lens mount M42 screw mount
Image sensor type film
Image sensor size 24 x 36 mm
Film format 35 mm
ASA/ISO range 20 - 1600
Film speed detection No
Focus Manual focus
Exposure Manual exposure
Exposure metering Average, through the lens (TTL)
Flash FP or X
Flash synchronization 1/60
Shutter speed range 1000 - 1 , B
Viewfinder pentaprism eye-level viewfinder with a microprism focusing screen
Battery Earlier model (SP) use RM400 battery; later models use PX625, but 1.5 V silver oxide batteries can be used due to bridge circuit
Made in Japan
All Pentax Spotmatics used the M42 screw-thread lens mount which was developed before WWII 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 camera allowed one to focus the lens at maximum aperture with a bright viewfinder image. After focusing, a switch on the side of the lens mount stopped the lens down and switched on the metering which the camera displayed with a needle located on the side of the viewfinder. The use of stop-down light metering was at the time revolutionary, but it limited the capability of the lightmeter, especially in 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.