other Pentax cameras in my collection:
Asahi Pentax KM [1975 - 1977]
There isn't very much that can be said about the Pentax KM: it is essentially a Spotmatic F with a bayonet mount, a slightly revised look, and an almost identical technical specification. The only significant difference (obviously aside from the new lens mount) is the relocation of the DOF preview button to the users right side of the camera - like Fujica ST series cameras. Perhaps that's why it's a bit of a forgotten camera? I can't imagine people rushing-out to replace their old Spotmatic with a model so similar, which also required the purchase of a whole new set of lenses.
The Pentax KM is additionally almost identical to the Pentax K1000 - one of the most enduring SLRs of all time, and introduced in the following year - but which lacked the KM's depth-of-field preview button and self-timer. Whilst the K1000 continued in production for decades, the other K series cameras were quickly replaced by the M series (initially the MX and ME), which where broadly similarly, but much smaller.
Three K models were introduced in 1975: the KM, KX and K2.
The KX featured a better TTL light meter using SPD, match-needle metering, aperture and shutter speeds in the viewfinder, and a mirror lock-up mechanism. It cost about 10% more than the KM.
The K2 was the flagship model - more like an ES II - and incorporated aperture priority auto-exposure via a step-less, metal bladed, Seiko shutter, plus match-needle manual metering. The K2 was almost twice the price of the KX. A further version, the K2DMD, accommodated a motor drive and data back.
Camera User magazine test report on the K series - unknown publication date, but appears to be very early in 1975.
The K series were fine cameras, but big, heavy, and outdated designs. They give the impression of having been rushed to market: there are small design incongruities between the models, such as the flash sync ports appearing in different places.
According to an advertisement in the November 1975 edition of
Camera User magazine, the cost of the recently launched Pentax KM body was £101.00. The same seller listed the Spotmatic F body for £123.20. By January 1977, according to Practical Photographer magazine, the typical price of a KM body was £98.32, which was about the same as the average weekly UK pay. The Pentax KM also came in black, and cost a few pounds more.
Lens mount: Pentax K.
Focus: Fresnel lens and micro-prism. 0.89x magnification and 93% viewfinder coverage. DOF preview.
Shutter: Horizontal rubberised silk focal plane with speeds of 1 sec - 1/1000th + B, and self-timer.
Meter: Open aperture, Cds meter, TTL average brightness, match needle visible in viewfinder. Auto iris.
Film Speed: 20 to 3200 ASA.
Flash: Standard X and FP synch, with X-synch hot shoe at 1/60.
Film Advance: Ratchet type rapid wind lever. 10° pre-advance and 160° advance angle.
Frame Counter: Automatic count-up and reset.
Rewind: Via crank and bottom release button.
Size: 143 x 91 x 52mm (W x H x D).
Battery: 1.5v LR44 type.
I paid £14.90 for this camera in December 2013. Oddly, the KM is a better specified camera, yet doesn't command a fraction of the cost of a K1000.
It has to be said - I'm not a big fan of the K1000. I tend not to like anything
popular, and I feel the K1000's status (as the camera recommended for students) is undeserved: there are others that offered the simplicity of the Pentax, but did it better (article link). I'm also slightly ambivalent about the KM.
I love the Spotmatic, but the KM somehow lacks its charm. It's a bit like when your favourite chocolate bar gets a new wrapper, and you wonder - what was the point of that; it still tastes the same but it's somehow become less familiar. The small styling changes just don't work for me ... like the elegantly curved wind arm tip becoming plastic, ditto the self-timer setting lever, the flow of the prism housing/mirror box being broken by a black line (makes it look like a Praktica), the previously subtle brand logo changing to a bold font, and the small cost cutting bump on the top plate, which covered a hole used for the battery check button on the KX.
On the plus side, what the KM offers is access to a massive range of PK mount lenses, so it is potentially the most flexible camera system in my collection. Now I remember why I bought it!
My camera is in good working condition. I've replace the light seals and mirror damper. I'm looking-out for a suitable Pentax K series (i.e. not an M or A series) lens for this camera, but good ones are un-common and expensive. And there's the irony: the camera with possibly the greatest number of lens options is one of the few in my collection that doesn't have a lens.