Instance Method

rampToVideoZoomFactor:withRate:

Begins a smooth transition from the current zoom factor to another.

Declaration

- (void)rampToVideoZoomFactor:(CGFloat)factor withRate:(float)rate;

Parameters

factor

The new magnification factor.

rate

The rate at which to transition to the new magnification factor, specified in powers of two per second.

Discussion

Allowed values for factor range from 1.0 (full field of view) to the videoMaxZoomFactor specified by the active capture format.

During a ramp, the zoom factor changes at an exponential rate, but this yields a visually linear transition. The rate parameter controls the speed of this transition independent of direction; for example, a value of 1.0 causes zoom factor to double every second if zooming in (that is, if the specified factor is greater than the current videoZoomFactor) or halve every second if zooming out.

Before calling this method, you must call lockForConfiguration: to acquire exclusive access to the device’s configuration properties. If you do not, calling this method raises an exception. When you finish configuring the device, call unlockForConfiguration to release the lock and allow other devices to configure the settings.

See Also

Managing Zoom Settings

videoZoomFactor

A value that controls the cropping and enlargement of images captured by the device.

minAvailableVideoZoomFactor

The minimum zoom factor allowed in the current capture configuration.

maxAvailableVideoZoomFactor

The maximum zoom factor allowed in the current capture configuration.

rampingVideoZoom

A Boolean value that indicates whether a zoom transition is in progress.

- cancelVideoZoomRamp

Smoothly ends a zoom transition in progress.

virtualDeviceSwitchOverVideoZoomFactors

An array of video zoom factors at or above which a virtual device, such as the dual camera, may switch to its next constituent device.

Beta
dualCameraSwitchOverVideoZoomFactor

The video zoom factor at which a dual camera device can automatically switch between cameras.

Deprecated

Beta Software

This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.

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