Nikon D300 D300 User's Manual - Page 112

D Focusing with Contrast-Detect Autofocus Contrast-detect autofocus will take longer than normal (phase-detection) autofocus. In the following situations, the camera may be unable to focus using contrast-detect autofocus: • The camera is not mounted on a tripod • The subject contains lines parallel to the long edge of the frame • The subject lacks contrast • The subject in the focus point contains areas of sharply contrasting brightness, or the subject is lit by spot lighting or by a neon sign or other light source that changes in brightness • A cross (star) filter or other special filter is used • The subject appears smaller than the focus point k • The subject is dominated by regular geometric patterns (e.g., windows in a skyscraper) • The subject is moving Note that the focus point may sometimes be displayed in green when the camera is unable to focus. Use an AF-S lens. The desired results may not be achieved with other lenses or teleconverters. A Remote Cords If the shutter-release button on a remote cord (available separately; see pg. 369) is pressed halfway for over a second in tripod mode, it will activate contrast-detect autofocus. If the remote cord shutter-release button is pressed all the way down without focusing, focus will not be adjusted before the picture is taken. 86