The Pentax SL is a meterless version of the Pentax Spotmatic SP camera, the two cameras are identical save for the meter. The Spotmatic cameras were a popular line of 35mm SLRs produced by the Asahi Optical Company in Japan, in the 1960s and 70s. The SL has a cloth, focal plane shutter capable of a top speed of 1/1,000th of a second, running down to 1 second, plus a Bulb mode. Like other Spotmatics, the SL uses the M42 threaded lens mount. Pentax did manufacture an add-on meter that attached to the top of the camera, in order to give the SL metering capabilities. This camera also has a self-timer.