IDS Software Suite - obsolete functions 4.97

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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 the "Camera and sensor data" chapter in the uEye manual.

Note on settings with influence on exposure time

The use of the following functions will affect the exposure time:

•is_PixelClock()

•is_SetOptimalCameraTiming()

•is_SetFrameRate() (if the new image duration is shorter that the exposure time)

•is_AOI() (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.

Note on exposure time increment

The increments for setting the exposure time (IS_GET_EXPOSURE_INCREMENT) depend on the sensor's current timing settings (pixel clock, frame rate). The smallest increment always corresponds to the duration of one pixel row, which is the time it takes the sensor to read out one pixel row.

Some sensors allow setting the exposure time with a finer increment (IS_GET_EXPOSURE_FINE_INCREMENT). This function is currently only supported by the sensors of the UI-124x/UI-324x/UI-524x and UI-125x/UI-325x/UI-525x models.

Note on rounding errors

When calculating a new exposure time based on the ..._INCREMENT parameter, please note that calculations with floating point values in the PC will always be subject to rounding errors. Therefore, an addition or subtraction of an n*INCREMENT value might not always produce the exact desired result. In this case, the uEye API rounds down the floating point value and sets the exposure time to the next lower value.

You can avoid this behavior by additionally adding or subtracting the value INCREMENT/2.f (half intervall) when calculating with n*INCREMENT. This ensures that the desired value will be set even after rounding.

Input parameters

Return values

Related functions

•is_SetFrameRate()

•is_Exposure()

•is_PixelClock()

•is_SetOptimalCameraTiming()

•is_SetAutoParameter()