Introduced back in 1976 by Pentax, the MX is a professional, all-manual 35mm film SLR camera. One of it's most appealing features is the compact body, combined with one of the largest and brightest viewfinders of any film SLR with 95% of photograph area visible and life sized 0.97X magnification with 50mm lens at infinity. The viewfinder info panel shows the chosen f/stop on the lens via aperture readout prism window, shutter speed and tri-colored (green/orange/red) LED read-out dots.
Pentax MX's shutter is fully mechanical Leica-type dual-cloth-curtain, horizontal-travelling-slit, focal-plane type using rubberized silk cloth curtains with speeds from 1 to 1/1000 sec. and doesn't need battery for it to take a photograph. The only battery dependent functionality is the built-in lightmeter: there are no auto-focus or auto-exposure modes such as aperture-priority, shutter-speed priority, or full program.
In case you've been looking for the ultimate compact film SLR camera that is compatible with the widest variety of lenses — from M42 to P/K mount — then you are already shooting Pentax MX.
What was true in 1976 is still true in 2019—and I bet—will be true in 2020, 2030... that is unless camera manufacturers wake up from the digital digisaster they got themselves into.
Back in the 1970's, Nikon and Canon were building bulky, nut-cracking, film tractors and compact 35mm film SLR cameras was not their forte. After all, they wanted to add every feature under the sun to their camera bodies, because their target audience was amateur photographers in search for feature creep.
While Olympus pioneered the compact 35mm film SLR concept with M-1(OM-1) in 1972, it was spoiled in execution by placing the shutter speed dial around the lens mount, douh.
Pentax MX's accessories included a film back capable of 250 photographs in one load as well as motorized winder Winder MX (2 frame/s) or a Motor MX (5 frame/s)motor drive and a 2 fps winder, Data backs, Dial Data MX, besides numerous other accessories.
A number of focusing screens were produced
- SC1: ground glass, split image device, microprism ring (standard)
- SA1: ground glass, microprism patch
- SA3: ground glass, microprism patch, for wide aperture lenses
- SB1: ground glass, split image device
- SD1: ground glass, cross collimator
- SD11: aerial image, cross collimator
- SE: ground glass
- SG: ground glass, grid
- SI: ground glass, axis
The current shutter speed and relative aperture are visible in the viewfinder, the aperture via a window that projects the aperture value from the lens aperture ring into the viewfinder.
Exposure is set by adjusting shutter speed or lens aperture until a green LED lights up in the viewfinder. This is an electronic version of the match needle metering of the Pentax Spotmatic and KM series.
The Exposure meter is powered by two 1.5V silver oxide batteries (G13) and is designed to operate as open-aperture, center-weighted Through-The-Lens meter, using GPD cells for fast light response, with tri-colored LED exposure read-out, rapid wind lever and shutter release button acting as meter switch (Pentax MX's weak spots).
- Exposure range: EV1 - 19 (ASA100, f/1.4)
- Film speed index range: ASA 25. 1600.
Due to Pentax MX's complete lack of automatic functions, but excellent array of manual controls fitted in a compact package, the MX is often preferred as a film SLR camera complementary to a classic rangefinder cameras.