251SDK (Software development Kit)
© 2010 Thorlabs
7.3.84
is_SetExposureTime
Syntax
INT is_SetExposureTime (HIDS hCam, double EXP, double* newEXP)
Description
Using is_SetExposureTime(), you can set the exposure time (in milliseconds). Since this value
depends on the sensor timing, the exposure time actually used may slightly deviate from the value
set here. The actual exposure time is returned by the newEXP parameter.
In free-running mode (is_CaptureVideo() ), any modification of the exposure time will only
become effective when the next image but one is captured. In trigger mode (
is_SetExternalTrigger() ), the modification will be applied to the next image.
For minimum and maximum exposure times as well as other sensor-based dependencies, please
refer to Specifications: Sensors chapter.
Newer driver versions sometimes allow an extended value range for the exposure time setting. We
recommend to query the value range every time and set the exposure time explicitly.
The use of the following functions will affect the exposure time:
is_SetPixelClock()
is_SetOptimalCameraTiming()
is_SetFrameRate() (if the new image duration is shorter that the exposure time)
is_SetAOI() (if the image size is changed)
is_SetSubSampling()
is_SetBinning()
Changes made to the window size, the frame rate or the read-out timing (pixel clock frequency)
also affect the defined exposure time. For this reason, you need to call is_SetExposureTime()
again after such changes.
Input Parameters
New desired exposure time
For EXP=0.0, the exposure time is 1/frame rate.
Returns the current exposure time in the newEXP
parameter.
Returns the default exposure time.
IS_SET_ENABLE_AUTO_SHUTTER
Enables the auto exposure function.
Returns the exposure time actually set.
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