The Spotmatic SP[]

=== 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. ===

  1. Mercury batteries are now banned; "Zinc-Air" cells can now be used instead, or it is possible to carry out a minor modification to the meter circuit to allow the use of 1.55 volt 387S silver-oxide cells.

The SL[]

Similar to the SP but without light metering

The SP500 and SP1000[]

Similar to the SP, but without self timer and max speeds of 1/500 (SP500) and 1/1000 (SP1000) The SP500 actually has a 1/1000 shutter speed one click past 1/500, although not marked on the shutter speed dial. It may not be an accurate 1/1000 speed, however; since the accuracy of that speed relies on careful selection of a speed cam, which was not done on SP500 bodies.

The Spotmatic SP II[]

An updated version of the original Spotmatic SP, launched in 1971. As well as a number of minor improvements to the meter components and film transport, the SP II was fitted with a HotShoe with a switch under the rewind crank for FP and X-flash synchronization and the ASA range was increased to 3200.

The Spotmatic SP IIa[]

Virtually identical to the SP II, but with an "electric eye" introduced to support the Honeywell line of dedicated flashes. It was only available in the North American market.

The Spotmatic SP F[]

Spotmatic , body only

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.


The ES[]

Automatic exposure (aperture priority) and manual mode camera with automatic speeds from 1-1/1000 and manual speeds from 1/60 - 1/1000 seconds. The light meter operates only when the shutter button is pressed and only in auto mode and the meter needle now indicates the auto shutter speed. Open-aperture metering with the S-M-C and SMC Takumar lenses, as for the SP F, is maintained. This camera is powered by one 4SR44 6.2v silver oxide battery and there is a battery check button.

The ES II[]

Similar to the ES, but with a self timer, shutter release lock, interior viewfinder blinds and shutter speeds from 8 seconds to 1/1000th second in auto mode. The power supply is now four modern 1.5v alkaline or silver oxide cells.



Kepler H. 1974 The Pentax Way. 8ed. Focal Press, London