All Pentax Spotmatics used the M42 screw-thread lens mount which was developed after World War II by Zeiss and Praktica.

These were high-quality, progressively improved lenses, later versions of which featured multi-coating and were called Super Multi Coated Takumars.

This camera allowed one to focus the lens at maximum aperture with a bright viewfinder image.

The original 1964 Spotmatic was one of the first SLRs on the market to offer a through-the-lens (TTL) exposure metering system.

A hot shoe for flash was added and the synchronization (FP or X) was placed on a dial switch located below the rewind crank.

The ES had standardized and improved circuitry that addressed reliability issues in the original version.

This camera, together with a revamped line of Super Multi Coated (S-M-C) Takumar had the capability of metering without stopping the lens down.