KSPROPERTY_CAMERACONTROL_FOCUS_RELATIVE

KSPROPERTY_CAMERACONTROL_FOCUS_RELATIVE

The KSPROPERTY_CAMERACONTROL_FOCUS_RELATIVE property specifies the focus setting of the camera.

Usage Summary Table

GetSetTargetProperty Descriptor TypeProperty Value Type

Yes

Yes

Filter or node

KSPROPERTY_CAMERACONTROL_S or KSPROPERTY_CAMERACONTROL_NODE_S

LONG

 

The property value (operation data) is a LONG that specifies a camera's relative focus setting. The size of the value represents the speed at which the focal point changes; a higher value represents a higher speed.

ValueDescription

0

Stop focus motion.

Positive value

Start moving the focus closer to the object.

Negative value

Start moving the focus farther away from the object.

 

Remarks

When making a set request, provide one of the values in the preceding table in the Value member of the KSPROPERTY_CAMERACONTROL_NODE_S structure.

When making a get request, the client receives one of the values in the preceding table in the Value member of the KSPROPERTY_CAMERACONTROL_NODE_S structure. The value indicates the current focus setting for the camera.

Note that a particular device might support only a certain speed range. To determine the range of speeds supported by the device, an application can issue a KSPROPERTY_TYPE_BASICSUPPORT request. You can specify KSPROPERTY_TYPE_BASICSUPPORT in the Flags member of the KSPROPERTY_ITEM structure.

Some devices support only a single focus speed. In this case, the sign of the Value member simply indicates whether the lens should shorten its focus or lengthen it.

Requirements

Version

Available for Windows Vista and later versions of the Windows operating system.

Header

Ksmedia.h (include Ksmedia.h)

See also

KSPROPERTY_CAMERACONTROL_NODE_S

 

 

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