All professional photographers know the ability to achieve pin-sharp shots is essential. It doesn’t matter how thrilling the subject or how inspired the photo composition. Even a minute hint of blur can mark the difference between an award-winning shot and a second-rate snap. If the eyes of a portrait are slightly soft and the eyebrows and tip of the nose are sharp, for instance, the image will lack both impact and credibility.
Your digital camera can adjust the focusing automatically at the touch a button. Good quality autofocus systems can move the lens elements into position faster and more accurately than the human hand and eye can. This makes them invaluable for sports photography, documentary photography, natural history, paparazzi and fashion photographers, not to mention anyone with less than 20-20 vision.
Nailing the focus for every shot is far from straightforward, involving considerably more user intervention than a point and shoot approach. This is because the speed, complexity and accuracy of autofocus systems varies dramatically from camera to camera and in different shooting situations. [read]