temperature
By cooling the sensor chips the dark current production can be highly dropped (approx.
every 6 °C the dark current is cut in half)
2.
18.3.1.2.1 Correcting Dark Current
The dark current correction is a pixel wise correction where the dark current correction image
removes the dark current from the original image. To get a better result it is necessary to snap the
original and the dark current images with the same exposure time and temperature.
Note:
Dark current snaps generally show noise.
To correct the dark current pixels following steps are necessary:
Black out the lens completely1.
Set "OffsetAutoCalibration = Off" (Figure 3)2.
If applicable, change Offset_pc until you'll see an amplitude in the histogram (Figure 4)3.
Set exposure time according to the application4.
Set the (Filter-) "Mode = Calibrate"5.
Snap an image ("Acquire" with "Acquisition Mode = SingleFrame")6.
Finally, you have to activate the correction: Set the (Filter-) "Mode = On"7.
Save the settings including the correction data via "Action -> Capture Settings ->
Save Active Device Settings"
(Settings can be saved in the Windows registry or in a file)
8.
The filter snaps a number of images and averages the dark current images to one correction image.
Note:
After having re-started the camera you have to reload the capture settings vice versa.
18 Use cases
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