Pco dicam C1, Руководство пользователя

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9.3 MATCHING THE 4 IMAGE INTENSIFIERS
During production process, PCO tries to select and group four image
intensifiers with similar image intensifier characteristics for a
pco.dicam C4 camera.
The setting of the individual channels is adjusted for maximum
intensifier voltage, so that the customer achieves the most
homogeneous intensity result comparing the images of all four
channels.
Additional fine tuning is possible to improve the channel matching at
any desired image intensifier voltage different from the maximum or
to compensate for aging effects of the image intensifier.
To set image intensifier voltage value, see
8.3
.
Procedure for Matching the 4 Channels
Set all 4 channels to maximum image intensifier voltage and same
exposure time. Point the camera to a homogeneous object, e.g. a
white wall.
Try to adjust the amount of illumination so that about 25% of
saturation level (16.000 counts) are achieved as a mean value.
Compare the mean values of all four channels.
The channel with the lowest mean value in the histogram (see
pco.camware manual, chapter 3.3.8 Convert Control) is left at
maximum intensifier voltage. The intensifier voltages of the
other three channels are stepwise reduced until all of them
reach the mean value of the previously identified weakest
channel.
Note that this method might not produce perfect homogeneous
results over the full dynamic range due to the non-linearity of the
image intensifiers.
So it may well be that for a signal level of e.g. 1000 counts all four
channels show approximately the same mean value, but differ for
higher or lower signal level.
Of course, if you want to invest more time, you can still perform a
subsequent calibration with the classical means of image processing.