Advanced Autofocus technology
Canon’s Advanced Autofocus Technology keeps images in focus so camera operators can concentrate on the shot. It employs a TTL-Secondary Image Registration Phase-detection system, originally developed for single-lens reflex still cameras, to ensure both high-accuracy and a high tracking capability. Two autofocus operating modes are available as well as a choice of three positions of the AF frame in the viewfinder.
Image Stabilization Technology
A built-in Optical Shift Image Stabilizer (identified by Shift-IS) system that effectively removes image stabilities especially at the telephoto extremes of the lens. This is a second generation system that embodies new refinements including separate horizontal and vertical control with high / low sensitivity settings.
Second-generation precision digital servo systems using Canon-developed 16-bit optical rotary encoder devices ensure high precision and repeatability of the Zoom and Focus settings. Encoders report to the 32-bit CPU – which, in turn, calculates during the focusing actuation to tightly control a synchronized zoom counter action that eliminates focus “breathing”. This Constant Angle Focusing System is identified by the CAFS logo.