It is intended to offer the AF speed of ring - type USM with the quietness of STM mechanisms ( see below ) .
Nano USM was introduced in 2016 with the release of Canon 's latest iteration of the EF - S 18 -- 135mm lens .
USM is intended to offer the AF speed of ring - type USM with the quietness of STM mechanisms ( see below ) .
Nano USM was introduced in 2016 with the release of Canon 's latest iteration of the EF - S 18 -- 135mm lens .