Pentax Spotmatic SP F (1973)

Pentax Spotmatic SP F (1973)

#366

This photo is from the copy I own.

Camera donated by Jorge Oliveira. Thank you!

History and technical features 

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 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, specially 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.

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.

Source: wikipedia.org

=== The Spotmatic was introduced by Asahi in 1964 and was the first camera to sell well with Through-the-Lens light metering. The camera was entirely mechanical apart from the light meter, which was powered by a 1.35 volt PX400 mercury cell[1]. A small switch on the (photographer's) left side of the lens housing was pushed up to stop down the lens and activate the meter; the exposure controls would then be adjusted to centre a needle on the right edge of the viewfinder. The body took lenses with a 42mm Pentax/Praktica screw thread, giving a huge range of alternatives. The system became the workhorse of many professionals of the period. ===

Source: camerapedia


Specifications

In 1973 the Spotmatic F joined the line. This camera, together with a revamped line of Super Multi Coated (S-M-C) Takumar had the capability of metering without stopping the lens down.

Source: wikipedia.org

Type: SLR body
Manufacturer: Asahi Optical Co.
Year of launch: 1964
Films: 35mm, speeds up to 1600 ASA
Viewfinder: pentaprism eye-level viewfinder
Lens Mount: Pentax/Praktica screwmount (M42)
Shutter: Focal plane shutter, speeds 1 - 1/1000 second, flash sync 1/60 second
Metering: CdS TTL metering (stopped-down manual match-needle metering system) EV 1.7 ~ 18 (ISO 100) ASA range 20-1600 (on original Spotmatic)

The Spotmatic SP F, launched in 1973, included several improvements. It was the first version to offer open-aperture metering, but this needed the updated Super-Multi-Coated (S-M-C) Takumar lenses with an aperture-position linkage to the camera. The FP option for the hot shoe synchronisation was dropped and the meter circuit design was revised to take account of the lens aperture setting and to indicate correct exposure when zero current is flowing through the meter, which now allowed for a variation in voltage from the battery. The battery now needed extra capacity and was changed to the now-defunct PX625 mercury cell. The light meter is constantly switched on but there is an automatic cut-off when the light is at EV2 or less, so it is important to keep the lens cap on when the camera is not in use, in order to conserve the battery.

Source: camerapedia


Model

Serial number 6145829


Reference sites

camerapedia

wikipedia.org


Manual

English manual


Batteries

PX625 battery

Film


Pictures taken with this machine


Videos