About PENTAX Focus Function

Autofocus is activated when combined with a camera that has an autofocus function.


Autofocus driven by the supersonic motor in lens body.

(Supersonic Direct-drive Motor) Small motors manage the actual focusing of an autofocus system. With the “Supersonic Direct-drive Motor” PENTAX has developed a technology that propels the focusing procedure with an ultrasonic motor. PENTAX SDM lenses drive the autofocus system significantly faster and operate more quietly than conventionally driven AF lenses.


Autofocus driven by the DC motor in lens body.

DC Smooth autofocus operation using an AF driving motor (DC Motor) installed in the lens barrel.


Autofocus driven by the pulse motor (stepping motor) in lens body

Body AF

Autofocus using the motor in the camera body.

*The autofocus on a body AF lens operates when paired with a camera equipped with an autofocus function. When paired with a camera that does not have an autofocus function, it can be used with as a manual focus lens.

*AF-compatible models for SDM, DC, PLM lens drive: K-70/K-1/K-3II/K-3/K-S2/K-S1/K-50/K-30/K-5 II/K-5IIs/K-5/K-01/K-7/K-r/K-x/K-m/K20D/K200D/K10D FW Ver.1.30/K100D Super

Focus Control System

Power focus

The amount of rotation of the distance ring is detected, and the motor in the lens barrel is operated using an electrical signal.
Since there is little backlash, high-precision manual focusing can be done. When the power is off, the focus does not work.