内容

• 特性
• 方法
• 详细描述

CameraExposure QML Type

An interface for exposure related camera settings. 更多...

import 语句：

import QtMultimedia 5.12

• 所有成员列表，包括继承成员

特性

• aperture : real
• exposureCompensation : real
• exposureMode : enumeration
• iso : int
• manualAperture : real
• manualIso : real
• manualShutterSpeed : real
• meteringMode : enumeration
• shutterSpeed : real
• spotMeteringPoint : QPointF
• supportedExposureModes : list<ExposureMode>

方法

• setAutoAperture ()
• setAutoIsoSensitivity ()
• setAutoShutterSpeed ()

详细描述

CameraExposure allows you to adjust exposure related settings like aperture and shutter speed, metering and ISO speed.

It should not be constructed separately, instead the exposure property of the a Camera should be used.

Camera {
    id: camera
    exposure.exposureCompensation: -1.0
    exposure.exposureMode: Camera.ExposurePortrait
}
					

Several settings have both an automatic and a manual mode. In the automatic modes the camera software itself will decide what a reasonable setting is, but in most cases these settings can be overridden with a specific manual setting.

For example, to select automatic shutter speed selection:

camera.exposure.setAutoShutterSpeed()
					

Or for a specific shutter speed:

camera.exposure.manualShutterSpeed = 0.01 // 10ms
					

You can only choose one or the other mode.

特性文档编制

aperture : real

This property holds the current lens aperture as an F number (the ratio of the focal length to effective aperture diameter).

另请参阅 manualAperture and setAutoAperture() .

exposureCompensation : real

This property holds the adjustment value for the automatically calculated exposure. The value is in EV units.

exposureMode : enumeration

This property holds the camera exposure mode.

The mode can be one of the following:

值	描述
Camera.ExposureManual	手动模式。
Camera.ExposureAuto	自动模式。
Camera.ExposureNight	夜间模式。
Camera.ExposureBacklight	背光曝光模式。
Camera.ExposureSpotlight	聚光灯曝光模式。
Camera.ExposureSports	亮点曝光模式。
Camera.ExposureSnow	Snow exposure mode.
Camera.ExposureBeach	Beach exposure mode.
Camera.ExposureLargeAperture	Use larger aperture with small depth of field.
Camera.ExposureSmallAperture	Use smaller aperture.
Camera.ExposurePortrait	肖象曝光模式。
Camera.ExposureAction	Action exposure mode. Since 5.5
Camera.ExposureLandscape	Landscape exposure mode. Since 5.5
Camera.ExposureNightPortrait	Night portrait exposure mode. Since 5.5
Camera.ExposureTheatre	Theatre exposure mode. Since 5.5
Camera.ExposureSunset	Sunset exposure mode. Since 5.5
Camera.ExposureSteadyPhoto	Steady photo exposure mode. Since 5.5
Camera.ExposureFireworks	Fireworks exposure mode. Since 5.5
Camera.ExposureParty	Party exposure mode. Since 5.5
Camera.ExposureCandlelight	Candlelight exposure mode. Since 5.5
Camera.ExposureBarcode	Barcode exposure mode. Since 5.5
Camera.ExposureModeVendor	The base value for device specific exposure modes.

iso : int

This property holds the sensor's ISO sensitivity value.

manualAperture : real

This property holds the aperture (F number) value for capturing photos.

If the value is less than zero, the camera automatically determines an appropriate aperture value.

aperture , setAutoAperture()

manualIso : real

This property holds the ISO settings for capturing photos.

If a negative value is specified, the camera will automatically determine an appropriate value.

另请参阅 iso and setAutoIsoSensitivity() .

manualShutterSpeed : real

This property holds the shutter speed value (in seconds). If the value is less than zero, the camera automatically determines an appropriate shutter speed.

shutterSpeed , setAutoShutterSpeed()

meteringMode : enumeration

This property holds the camera metering mode (how exposure is balanced).

The mode can be one of the following:

值	描述
Camera.MeteringMatrix	A matrix of sample points is used to measure exposure.
Camera.MeteringAverage	An average is used to measure exposure.
Camera.MeteringSpot	A specific location ( spotMeteringPoint ) is used to measure exposure.

shutterSpeed : real

This property holds the camera's current shutter speed value in seconds. To affect the shutter speed you can use the manualShutterSpeed 特性和 setAutoShutterSpeed() .

spotMeteringPoint : QPointF

The property holds the frame coordinates of the point to use for exposure metering. This point is only used in spot metering mode, and it typically defaults to the center (0.5, 0.5) .

supportedExposureModes : list < ExposureMode >

This property holds the supported exposure modes of the camera.

该特性在 Qt 5.11 引入。

另请参阅 exposureMode .

方法文档编制

setAutoAperture ()

Turn on auto aperture selection. The manual aperture value is reset to -1.0

setAutoIsoSensitivity ()

Turn on auto ISO sensitivity selection. The manual ISO value is reset to -1.

setAutoShutterSpeed ()

Turn on auto shutter speed selection. The manual shutter speed value is reset to -1.0