Camera Parameters; Pixel Clock, Frame Rate, Exposure Time; Gain And Offset - THORLABS DCU223x Operation Manual And Sdk

DCx Cameras

2.6 Camera Parameters

Pixel clock, frame rate, exposure time

Gain and offset

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Automatic image control
Applying new parameters
2.6.1 Pixel Clock, Frame Rate, Exposure Time
Pixel clock
The basic parameter for camera timing is the pixel clock. It determines the speed at which the sensor cells can be
read out.
Attention
We recommend not setting the pixel clock any higher than necessary to achieve the desired frame rate.
An excessive pixel clock can cause delays or transmission errors. If the data is read from the sensor at a higher
speed (high pixel clock), you will also need a faster transmission over the data connection. Thus, by controlling the
pixel clock, you can also influence the bandwidth required for a camera.
The pixel clock influences the connected load and consequently the temperature inside the camera.
Frame rate
The possible range of settings for the frame rate depends on the currently selected pixel clock. You can select a
lower frame rate without changing the pixel clock. To set a higher frame rate, however, you need to increase the
pixel clock.
Exposure time
The exposure time depends on the currently selected frame rate and is preset to its reciprocal value. You can
select a shorter exposure time without changing the frame rate. To set a longer exposure time, however, you need
to reduce the frame rate.
Note
The increments for setting the exposure time depend on the sensor's current timing settings (pixel clock, frame
rate). The exposure time values are rounded down to the nearest valid value, if required. For this reason, the actual
exposure time can deviate slightly from the exposure time you have selected.
See also:
uc480 Viewer: Camera
is_PixelClock()
is_SetFrameRate()
is_Exposure()
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2.6.2 Gain and Offset
Gain
In digital imaging, a voltage proportional to the amount of incident light is output by the sensor. To increase image
brightness and contrast, this signal can be amplified by an analog gain and offset before the digitizing process. The
results of analog signal processing are usually better than the results of digital post-processing.
Analog amplification of the read-out pixel values increases overall image brightness and contrast. Depending on
the sensor type, a global gain value for all pixels (master gain) or a separate gain value for each color (RGB gain)
can be set.
Note
Using Sensor Gain: A signal gain will also result in a noise gain. High gain settings are therefore not
recommended.
We suggest the following gain settings:
1. Enable the Gain boost
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function (is_SetGainBoost()
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