Itala | INSTRUCTION MANUAL
Figure 48: Correct alignment between illumination and camera expo-
sure time. From top to bottom, the triggering signal, the illumination
period and the camera exposure time are depicted.
6.3.4 Timed vs TriggerWidth Exposure Mode
Exposure mode can be either Timed or TriggerWidth.
When Timed Exposure is selected, the sensor exposure time is set using the ExposureTime or Ex-
posureAuto features.
In this case the exposure time can be expressed as follows:
SensorExposureT ime = ExposureT ime (2)
For example, if ExposureT ime = 500µs, the image sensor is exposed for 500µs.
When TriggerWidth Exposure is selected, the exposure duration is equal to the width of the cur-
rent Trigger signal pulse.
Actually, for some image sensors, the real exposure time can be computed as follows:
SensorExposureT ime = T riggerP ulse + ExposureOf f set (3)
where:
• SensorExposureTime is the overall exposure time of the image sensor.
• TriggerPulse is equal to the external trigger signal.
• ExposureOffset is an additional intrinsic period in which the image sensor is collecting light.
In this case, if the Trigger pulse supplied to the camera is equal to 500µs, also the intrinsic contri-
bution of the sensor exposure offset must be taken into account, leading to an overall exposure
time higher than 500µs.
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