Pentax
Japanese camera maker, formerly Asahi Optical, known for the Spotmatic and the simple K1000.
Asahi Optical began with spectacle lenses and went on to make lenses and cameras. The Asahiflex of 1952 was one of the first Japanese single-lens reflex cameras.
The Spotmatic of 1964 metered light through the lens, and the K1000 of 1976 was the photography-school camera for decades. The brand is now part of Ricoh.
The name Asahi Pentax on the prism.
The K bayonet, introduced in 1975 and still in use.