Mamiya's M42 SLR — the DSX 500, TTL averaging and spot metering, mechanical shutter, 1974.
The Mamiya DSX 500 was a 35mm film SLR made by Mamiya using the M42 screw lens mount. It belonged to Mamiya's DSX line of the mid-1970s, which offered TTL metering on the widely supported M42 standard. The DSX 500 sat as the more basic of the paired DSX models, with the 1000 version above it, and was aimed at general users and students wanting an affordable interchangeable-lens camera.
It is a 35mm single-lens-reflex camera on the M42 screw mount, so it accepts the large range of M42 lenses from many makers. The horizontal-travel cloth focal-plane shutter is mechanically timed, and on the 500 the shutter tops out at a slower maximum speed than the 1000 model, as the naming indicates. Metering is TTL and offered both averaging and spot patterns on the DSX bodies, with match-needle exposure setting. Being mechanical, the shutter fires without a battery, which powers only the meter.
This body suits general, student and beginner photography, and travel where a simple, robust manual camera is wanted. The M42 mount gives access to a very wide and affordable selection of lenses, and the match-needle metering makes learning exposure straightforward. Its manual operation and mechanical shutter appeal to those who want a dependable camera with minimal electronics.
For a used purchase, check the mechanical shutter across all speeds for accuracy and capping. Test the meter and its battery, noting that meters of this era were often designed for mercury cells, so confirm what battery it takes and how it reads. Inspect foam light seals and mirror-damper foam for perishing, look through the finder for prism haze, and test film advance and rewind feel. The shutter still fires with a dead meter battery, but the meter needs power to work; check M42 lenses thread and stop down correctly.