Brightness And Sensor Signal Control; Exposure / Integration Time - Smartek Vision Giganetix GC Series User Manual

4 Image Acquisition

4.3 Brightness and Sensor Signal Control

4.3.1 Exposure / Integration Time

The brightness of an image is influenced by the amount of light that falls on the image sensor, concerning
both intensity and duration. The duration of time in which the photosensitive cells of the image sensor are
exposed to the incoming light is called the exposure time or the integration time. While the intensity of
light depends on the light source and the lens aperture, the exposure time can be controlled by modifying
parameters of the camera.
Figure 91 demonstrates two settings of camera's exposure time. The left picture is captured with an
exposure time of 10000 s. For the right picture the exposure time is set to 22000 s. The brightness
µ µ
difference of the two images is clearly visible. Due to the nearly linear behavior of the used sensors, doubling
the exposure time results in an approximately doubled pixel intensity.
Figure 91: Different exposure time settings
The exposure time for SMARTEK Vision digital cameras is configurable by the GenICam Float property
ExposureTime and expressed in microseconds ( s). Each camera has a predefined range of values,
µ
depending on the sensor and its technology. The minimum and maximum exposure time for each camera
model is shown in 2.2 - Sensor Information and Technical Specification (All Models Separate) and can be
determined programmatically via the IDeviceInterface of the gige API.
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SMARTEK Vision Giganetix User Manual Version 2.1.4