I was the US moderator for the Pentax LX Guestbook Messenger forum for at least 7 years (the other two were from Canada and the UK). The LX was issued in two runs, the first one was unreliable, the second was (research serial numbers). Both runs developed sticky mirror syndrome when the mirror bounce foam failed in time, and often developed failure of the self timer/DOF lever due to its attached push button activation access eventually de-threading its mechanism attachment and thus its possible operation (difficult to get repaired BTW). Its shutter, averaging center weighted meter, build, and quiet operation were accurate, did not hold memory between shots, and spoke quality. It had an accurate and long lasting quilted horizontal metal shutter. A working body can use any K mount lens with an on lens manual aperture adjustment. It signaled aperture to the body's meter through a mechanical linkage. Its auto exposure was achieved by aperture priority mode. It offered interchangable viewfinders, winder, and motor drive (with accessories). It was truly a system Professional film camera.
Both had metal bodies, the MX was simpler, with no autoexposure, yet with indexed lights set against a visible bracket in the viewfinder that made it easy to bracket exposure. It had a cloth shutter which would underlast the LX by two thirds longevity. Its simple electronics were prone to dust working its way under its bonnet through its shutter speed/ meter sensitivity dial; the LX was not so disposed (as had water resistant seals similar to the Pentax DSLR). The MX offered half and full stop over and under indexed lights averaging center weighted manually adjustable metering indicators. ASA/ISO settings were adjustable in 1/3 exposure stop increments. The MX was very lightweight and somewhat weather resistant in use with an integrated noninterchangeable viewfinder, I carried it backpacking a half dozen years. Fuji Velvia transparency film was my bread and butter from my shooting slide keepers library sales. It was better built than its alike sized predecessor, the Olympus OM1.
The LX and MX had a very similar viewfinder brightness and view area scope. LX Standard FA-1 Interchangeable Eye-Level Pentaprism Finder featured silver-coating and shows 98% vertical, 95% horizontal of picture area plus full data viewfinder display; and offers a built-in diopter correction by adjustment screw. The MX required a slip over glass lens back viewfinder eyeframe diopter correction. The LX finder was removable by a release lever. 7 other Prisms were available. The fixed MX viewfinder and changeable LX viewfinder focusing screens, though not multicoated for the MX, and multicoated for the LX, were interchangeable with one another.
The ME Super and Super (Program) A slightly different cameras offered more automation of exposure, without half stop manual metering (and offering push button shutter speed adjustments, and automatic shutter speed metering, and the Super [Program] A offering both aperture or shutter speed autoexposure with A series lenses which can still be set to A aperture automation on Pentax DSLRs) but used the same metering cell as the MX, and ME -- so were accurate, and did not hold memory between shots (which was a big metering advance over the K series cameras). The ME Super had a metal body, the A series plastic bodies. The winders on the LX, ME super, and MX were 2 fps, with the LX and MX also offering motor drives up to 5 fps. The Super A up to 3.5 fps for its now hard to find motordrive. The ME winder II fit both the Super Program and ME Super bodies. Any of their viewfinders were good, with the earlier K series bodies, MX, LX, and ME Super having pentaprisms. Only one A series had this, the cheaper units used penta mirrors.
The seals on the backs and mirror up bounce will rot after many years in a humid climate. But, finding one in pristine shape, from someone who purchased it and lodged it hardly used in a closet and case, is still very much possible. Good hunting.
If you wish to purchase one, condition is everything. I picked up a functional and clean ME Super body with winder II for under $30. The advantages of any of these are the now inexpensive, yet excellent M series SMC lenses, often with a common 49mm filter size, as are readily found on ebay for peanuts. I literally wore out the aperture on a 35mm f2, but enjoyed its color and rendition detail daily for 5 years, along with a 100mm M tele, an M series 2 28MM , and a 20mm f4 M with a 49mm filter which I still use. Occasional bargain lenses which would work well with the LX, M, and A series benefits are the M and A telezooms. I still hold 5 M series optics, used mostly for Video on digital bodies (with manually available aperture adjustment). The remote screw on 4 pin wired release for the LX MD and winder is interchangeable with the ME Super Winder II. The MX winder has no remote, unlike its motor drive, which interchanges batteries and AC power resources including a remote connection on then available battery packs with the LX.
