Another critical objective when shooting in High Definition is achieving a very sharp focus. Canon's revolutionary Instant AF focusing system offers a dramatic improvement in auto focus speed and accuracy (compared to traditional auto focus systems). The Instant AF feature uses an external sensor, in combination with Canon's auto focus system, to help significantly decrease the time it takes to find focus, even in low light conditions. This system achieves focus instantaneously, reducing focus "hunting." The benefits of Instant AF are especially seen in high brightness and night shooting situations. With Instant AF, it's possible to capture fast, accurate focusing, even when following a moving subject.