The K1000 is an almost all metal, mechanically (springs, gears, levers) controlled, manual-focus SLR with manual exposure control. It was completely operable without batteries. It only needed batteries (one A76 or S76, or LR44 or SR44) for the light metering information system. This consisted of a center-the-needle exposure control system using a galvanometer needle pointer moving between vertically arranged +/– over/underexposure markers at the right side of the viewfinder to indicate the readings of the built-in full-scene averaging, cadmium sulfide (CdS) light meter versus the actual camera settings. The meter did not have a true on/off switch and the lens cap needed to be kept on the lens to prevent draining the battery when the K1000 was not in use.
The viewfinder also had a focusing screen with a microprism spot focusing aid. The Pentax K1000 SE substituted a split image rangefinder plus microprism collar focusing screen. The K1000 SE is otherwise identical to the regular K1000, except that the SE's from the first few years of production used brown leather instead of black.