Pentax KX

Pick up a KX after a decade of screw-mount Spotmatic and the first thing your hand does is relax. Same compact heft, same right-thumb wind, same dense little body that does not rattle, but now a lens twists on and locks in a quarter turn instead of threading down forever. That is the K bayonet, a three-claw 45mm mount Pentax rolled out across the 1975 K-series, and the KX sat in the middle of the trio. Above it, the aperture-priority K2. Below it, the budget KM. The K1000 people picture when they hear "Pentax" did not exist yet.

That ordering matters, because the KX gets described against the wrong sibling. Its actual 1975 stablemate was the KM, which already had the self-timer and the depth-of-field preview, so those were never the upgrades. What the KX added over the KM was the meter and the finder. Pentax put a center-weighted silicon photodiode cell in it, fast and sensitive across a wide ISO range and good for its age, in place of the slower CdS metering below. The viewfinder is the reason to own one. Bright, and along the right edge a blue flag tied to the shutter speed dial swings against the meter needle, so you balance exposure by lining them up with no symbols to decode. A small window up top reads back the aperture you have set, so you can confirm a whole exposure without taking your eye off the frame.

There is also mirror lock-up, built into the depth-of-field preview control on the front: rotate the collar around the preview button and press it. It is the sleeper feature. Flip the mirror up before a long-lens or macro frame where slap would soften everything, and the curtains fire clean. The shutter under it is a horizontal cloth focal-plane unit, 1 second to about 1/1000, sync at 1/60. Nothing exotic. But it is fully mechanical, which is the part that ages well.

Know this before you buy. The KX takes two 1.5V silver-oxide cells, an SR44 or S76 or equivalent, the correct modern cell straight off the shelf. Because the meter runs on a silicon photodiode and not a CdS bridge, there is no 1.35V mercury supply to fake and no voltage-mismatch drift to correct for. Fresh SR44 and it reads true. The cell only ever powers the meter. With a dead battery the KX still fires at every speed, exactly like the K1000 does, you just lose the needle. The honest difference between this body and the famous K1000 is feature count, not whether the shutter needs power. Neither one does.

The real weaknesses are age, not design. Fifty-year-old foam light seals crumble, and a meter unserviced for decades can read a stop off no matter what you feed it. A center-weighted needle is easy to fool, too. Point it at a bright sky behind a backlit subject and it will stop down and bury the face. For those frames, take a spot or incident reading from the Zone Light Meter app and place the shadows where you want them instead of averaging the scene and hoping. The K1000 became the student-camera legend and got expensive on reputation, so the better-equipped KX often sells for less while handing you more camera. Cross-shopped against the Nikon FM and the Olympus OM-1, on mechanical feel and finder clarity it holds the line. Buy one with fresh seals and a checked meter and it will outlast you.