Speed of Focusing
What does the speed of the AF depend on? The camera or the lens?
Aksa J Altaf, Srinagar, via email
This article was originally published in July 2014.
The simple answer? Both. The camera’s ability to lock focus on the subject will affect AF speed. Having more AF points helps the camera pinpoint focus better, thus making it faster to focus. Also, a camera tends to focus fast when cross-type AF points are selected.
Once the camera gives the lens a command to focus, each lens’ focusing speed will depend on the focusing motor of the lens. It will also depend on the kind of lens you use. Wide angle lenses are usually faster than telephoto lenses.
Prime lenses will usually focus faster than a zoom lens. Macro lenses have slower AF than other lenses of equal focal lengths.
Finally, lenses with a wide aperture will allow more light into the camera, helping it focus faster.