Tokina Opera 16-28MM F2.8 FF for Canon EF Mount

One-Touch Focus Clutch Mechanism Tokina's exclusive One-Touch Focus Clutch Mechanism allows the photographer to switch between AF and MF simply by snapping the focus ring forward for AF and back toward the lens mount for manual focusing.. Full Frame Sensor Size, opera 16-28mm F2.8 FF is available for Nikon F and Canon EF mounts.. Focal Length 16-28mm Maximum Aperture f/2.8 Minimum Aperture f/22 Automatic Aperture Yes Manual Aperture Ring No Angle of View 107°6'-76°52' Minimum Focusing Distance 0.28m Macro Ratio 1:5.26 Focusing Mode Automatic Manual Focusing Ring Yes Autofocus Switch Clutch Ring Focusing Type Internal Focus Sensor Size Full Frame Multi-coating Yes. Construction E/G 15 Elements in 13 Groups Aperture Blades 9 Electrical Contacts Yes. Fast and accurate AF The lens uses Silent Drive module that allows the lens to focus speedy and quietly. This DC motor, coupled with a new GMR magnetic AF sensor, works together to increase AF speed and accuracy.