Page 85 - (DK) Advanced Photography Guide

FO CUSING 83

AF point selection
The AF point selection mode you choose will slower by comparison. However, for slower-paced
depend on your subject. Auto is excellent for social shooting—for example, still life, architecture, and
situations where there may be little or no time to landscape—the precision of Single point selection
manually select an appropriate AF point; choosing outweighs this disadvantage. Zone selection is a
the right AF point in Single point selection is far useful bridge between the two modes.

AUTO SELECTION SINGLE POINT SELECTION ZONE SELECTION

With Auto selection, your camera In this mode, you manually select one Zone selection groups neighboring
decides which AF points set the focus. focus point from all those available. The AF points together to effectively form
You have no control, so it is not suitable main advantage of Single point selection one large AF point. You select the zone,
if you need highly precise focusing. Auto is that you have precise control over and the camera focuses on the nearest
usually focuses on the closest element where the camera focuses. This is useful point within it. There are far fewer zones
in the scene, so the camera may not if your subject is off-center or partially than AF points, so this mode is useful
focus on your subject if it is partially hidden, or when you want to focus on when you need to be able to jump
obstructed by something. a specific part of your subject. quickly between zones.

AF PROBLEMS

Despite their sophistication, modern AF systems still struggle to decide whether to attempt to focus on another part of the
to lock focus in certain conditions. When this happens the scene, ideally at the same focus distance as your subject, or to
lens will “hunt,” shifting focus indecisively, and you will have switch to manual lens focusing.

LOW CONTRAST LOW LIGHT MOVEMENT TEXTURE

Flat-toned subjects generally In low light, the AF system AF systems struggle with Fine-textured or busy surfaces
do not have the contrast that may not work efficiently. Try subjects that move quickly or can cause AF to fail. Solve the
AF needs to work effectively. to work around this by adding erratically. In these situations, problem by focusing on a less
Conditions that lower the a little light to the scene. Some try to prefocus and select a busy part of the scene—as
contrast, such as mist and flashes have an AF assist mode relatively small aperture to long as it is the same distance
fog, can also cause problems. for such situations. increase the depth of field. as what you want to capture.

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