pentax p3 manual focus 35mm film camera w/ 50mm lens pentax the pentax p3 was the first of four p-series cameras. it has lower specifications than the pentax super program/super a that was released two years earlier. it only has program and manual exposure modes, and the iso can only be set by the dx coding on the film canister, but it is the first pentax with an exposure lock which makes up somewhat for the lack of exposure compensation.