Mamiya's M42 SLR — the MSX 500, TTL averaging metering, mechanical shutter, 1974.
The Mamiya MSX 500 was a 35mm film SLR made by Mamiya on the M42 screw lens mount. It belonged to Mamiya's mid-1970s MSX line, a companion to the DSX series that used a simpler metering arrangement. The MSX 500 was the more basic of the paired MSX models, below the MSX 1000, and was aimed at general and student users wanting an affordable interchangeable-lens camera on the common M42 standard.
It is a 35mm single-lens-reflex camera on the M42 screw mount, accepting the wide range of M42 lenses from many makers. The horizontal-travel cloth focal-plane shutter is mechanically timed, and the 500 has a slower top speed than the 1000 as its name indicates. Metering is TTL averaging with match-needle exposure setting, without the spot option of the DSX bodies. Because the shutter is mechanical, the camera 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 large and inexpensive lens pool, and the averaging match-needle meter keeps exposure setting easy to learn. Its mechanical shutter and manual controls make it a dependable choice for those who prefer minimal electronics.
For a used purchase, check the mechanical shutter across all speeds for accuracy and capping. Test the meter and confirm what battery it takes, noting these meters were often designed for mercury cells and may read differently on modern replacements. Inspect foam light seals and mirror-damper foam for perishing, check the finder for prism haze, and test film advance and rewind. The shutter fires with a dead meter battery, but the meter needs power; confirm M42 lenses thread and stop down correctly.