All DSLR cameras have autofocus [AF] and although it is not essential, it certainly helps. Modern AF systems focus quicker than you can focus manually [M].
They are a great asset for spectacle wearers. However, there are still situations where manual focus works better than AF, such as in low light conditions ( in which case you just turn the AF off ).
Autofocus systems have two main modes, single shot and continuous. In single shot, you point the camera and it locks the focus on your subject until you take the photo or remove your finger from shutter release button. In continuous mode, the camera focuses continuously depending on what you point the camera at.
You must have/ turn to a continuous autofocus mode when shooting moving subject. All autofocus SLRs do.
Predictive AF is also used for moving subjects and is automatically switched on by the camera. Because there is a delay between when you press the shutter button and when the photo is exposed ( although only a fraction of a second ), the subject might move out of focus. Predictive AF ' predicts' the subject's change in position and sets the focus accordingly.
** You can turn the autofocus off if you don't want to use it..
No comments:
Post a Comment