Canon EF-S 18-135mm f/3.5-5.6 IS STM Review

Introduction The main novelty for this 7.5x zoom is its autofocus, christened STM (Stepping Motor Technology), that allows fingertip editing, but especially the ability to provide continuous tracking of moving objects both rapidly and quietly, making it perfectly able to answer the exigencies of video. According to Canon, this type of motor eliminates the “pump effect” that one sometimes encounters with other systems.Videographers will particularly appreciate its quietness, along with its electro-magnetic diaphragm (EMD) that allows for accurate and swift shutter control. The shutter consists of 7 circular leaves.The EF-S