Mid 1970s, Pentax was getting a little concerned, sales of its screw mount camera line were dropping off, M-42 was a great mount circa 1958, held its own in the mid 1960s but by 1975 was getting long in the tooth. Pentax collaborated with of all companies Zeiss Ikon to design the K mount in the late 1960s to come up with a joint lens mount The German partners decided to get out of the camera business altogether by the mid-1970s and Pentax made the K mount an open source technology. In an alternate universe if Zeiss Ikon kept making cameras, they would have K mounts but I digress.
Pentax dropped onto the market three cameras, the entry level KM which was a Spotmatic F with a K-mount for all intents and purposes (want to get one at some point), the KX which had a much better meter and the top of the line K2 which had a Seiko vertical Copal shutter which was electronically controlled with the ability to do aperture priority like the Nikkormat EL Minolta XE-7 and the Olympus OM-2, Canon was way off in left field with their EF and soon to be released AE-1 which embraced shutter priority.
The K2 was aimed squarely at advanced amateurs and the later and much rarer K2DMD which also had motor drive capability and a data back. While the KM was replaced by the K1000 by and large, and the KX was discontinued the much more compact MX in 1977 replacing it, the K2 remained in production until 1980 to be replaced indirectly by the LX which had a 20-year production run.
I got my K2 from a local camera show for $80 CAD and immediately put in some fresh Energizer 357's and an SMC Pentax M 50mm lens on. I wanted to try the camera out last week starting Thursday late afternoon downtown (photos below), it worked great. I finished the roll Saturday and the camera started flaking out. I had to remove and reinstall the batteries to almost "reboot" the camera. I got through the roll of Tri-X, processed and got, as usual, some great shots all things considered.
My theory was I was getting flakiness from dirty battery contacts, I should state up front there was no battery corrosion in the battery box which would have been really bad. To put that theory to the test I dipped a q-tip in some pure alcohol and cleaned the battery box as best I could, the q-tip came up grey. So, popped the batteries back in the camera immediately came back to life and fired consistently and the meter was giving solid readings. Another test roll is in order shot locally this time to draw a full conclusion.
Other than that, the K2 is a really nice camera it has the classic "Just Hold One" Pentax ergonomics with one glaring what the hell were the engineers and product designers were thinking, the film speed was on the lens mount like Nikkormat FT(n, 2 and 3). The film speed control on the K2 is known to become difficult to change and an opportunity to lose a fingernail if you're not careful. A CLA will fix this problem. The other weak spot is the exposure compensation is on the same lens mount, neat idea at the time, Pentax should have just copied with Nikon was doing with the Nikkormat EL and Minolta with the XE-7 with their film speed and exposure compensation controls and the K2 would have been perfect.
The market for K2s these days is all over the place, I got mine for $80 CAD, expect to pay more on Ebay, if you shoot K mount and you're looking for something a bit off the beaten path and LX prices are too rich for your wallet, give the K2 a look.
(Update June 22, 2018. It was dirty battery contacts, I shot a follow-up roll of Fomapan 100 with no issues.)
Camera: Asahi Pentax K2, SMC Pentax M 50 f1.4 lens.
Film: Kodak Tri-X 400, Tmax developer 1+4.