The K2 looks like it was also based on Spotmatic technology (with the mirror-up lever in the same spot as the old meter-on, for example) but appears to be aiming at something different. I'd suggest that that something different was the Nikon Nikkormat EL, which was introduced a few years earlier as Nikon's first electronic-shutter AE camera. The K2 is actually MORE like the EL than it is like other Pentaxes. The K2 looks like an attempt to match or slightly one-up the EL, starting from a Spotmatic body. If the goal were simply to make a K-mount AE camera, one would expect it to look a lot more like the existing ESII (a fine camera, from what I can tell).
Right, as the K2 sported an electronic vertical shutter, but what is notable here is that Pentax left the pool of manufacturers that were involved in the development of various Copal shutters (used in some Konica, Nikon, Canon, Yashica and Minolta-Leica auto-cameras) and went to Seiko for their first use of a metallic vertical shutter. The Seiko MF that came out of this collaboration is said to be smaller and working better than others' in extreme cold temperatures. As the ME uses the same shutter, I think Pentax was not ready to make a smaller camera at the time the Seiko MF was ready but they were probably working on that, probably from the moment the OM-1 camera proved to be a success...
I also wonder if "X" as in KX, ZX-M, etc, has been used in any consistant nomenclature sense. It could stand for "old fashioned", essentially. I'd argue for "mechanical" but for the ZX series.
Or X-cellent. Or X as a "variable", thus cameras where the user's input is needed. But it's only true for the KX, MX and ZX-M...
Andre
