autofocus system

Phase Detection autofocus system :In Phase Detection autofocus system, the camera uses a special sensor to detect the contrast of light entering the lens. Performed by detecting the contrast of the lens bend light using a mirror to the autofocus sensor two (instead of a photo sensor).The sensor is capable of detecting the phase difference of incoming light, as they do not coincide then the lens will continue to be driven. When the light phase is coincident (meaning the image is in focus), then the focus sensor will tell the camera to stop the movement of the lens and lock the focus.Contrast Detection autofocus system

In contrast to the phase detection system, contrast detection system cameras do not require additional sensors. These systems rely on the main sensor to detect whether the pattern of light from the lens is sharp or not.ApplicationContrast detection system, because it does not use a mirror (mirror) is usually used by mirrorless cameras and compact cameras.While the phase detection autofocus system because it requires the mirror is usually used by digital SLR cameras. DSLR cameras can also take advantage of these two system simultaneously. When operating normally using Phase Detection DSLR, while the live video recording mode and when they put on Contrast Detection.NatureBoth system require the existence of sufficient light, besides that they also need a photograph objects that have sufficient contrast to be easily detected. When you shoot all the white smooth walls, will continue to rotate the lens to focus. This occurs because as the camera takes a prominent object or shape than the smooth white walls. Suppose the wall there is a black nail, then it is easy for the camera to lock focus on the black nail that stands out because it has a contrast between the white sea.Advantage and disadvantagePhase Detection system today is much faster in lock focus, so that they excel when used to capture moving objects. However, the accuracy, Contrast Detection is more accurate though more slow in finding and locking the focus. DSLR cameras are generally outperformed the autofocus speed compared mirrorless camera or pocket camera that uses contrast detection.