Ultra-wide-angle constant F4 APS-C power zoom lens Excellent G lens resolution throughout the 10 to 20 mm zoom range (35mm full-frame equivalent: 15 to 30 mm) Responsive new power zoom system and a zoom lever that makes it easy to execute super-slow constant-speed zooms Two linear motors allow fast, precise autofocus and tracking performance for both stills and movies. Advanced lens technology reduces focus breathing as well as focus and axial shift when zooming so that quality images can be easily captured.