In 2012, Canon introduced the STM (Stepper Motor), designed to meet the needs of video recording by providing smooth, quiet autofocus. The STM operates by sequentially applying electric current to coils, generating small, precise stepping movements that allow accurate focus control and minimize noise — ideal for filmmaking.
There are two types of STM: gear type for compact lenses and lead-screw type for larger lenses, each optimized for different applications.
