Basler L800k, User Manual, Page: 55 / 168

Operation and Features
BASLER L800
k
3-15
Draft
3.6.3 Offset
When the camera is set for 8 bit output, offset is adjustable within a range from -200.0 to +200.0
DN (digital numbers) in increments of 0.5 DN. When the camera is set for 10 bit output, the range
is from -800.0 to +800.0 DN and is adjustable in 0.5 DN increments.
Increasing the offset by one will cause the average pixel value for each line transmitted by the
camera to increase by one digital number. Decreasing the offset by one will cause the average
pixel value for each line transmitted by the camera to decrease by one digital number.
3.6.3.1 Setting the Offset
You can set the offset with the Camera Configuration Tool Plus (CCT+) or by using binary write
commands from within your own application to set the camera’s control and status registers
(CSRs).
With the CCT+
With the CCT+ (see Section 4.1 ), you use the Offset parameter in the Gain & Offset parameters
group to set the offset.
By Setting CSRs
You set the offset by writing a value to the Absolute Offset field or to the Raw Offset field of the
Offset CSR (see page
4-26 ).
Section 4.2.2 explains CSRs and the difference between using the “absolute” field and the “raw”
field in a CSR. Section 4.3.1 explains using read/write commands.
3.6.4 Offset Balance
As mentioned in Section 3.1 , the odd pixels in the left half of the CCD sensor, the even pixels in
the left half of the CCD sensor, the odd pixels in the right half of the CCD sensor and the even
pixels in the right half of the CCD sensor are processed through four different electronic channels.
When you change the global offset setting as described in Section
3.6.3 , you apply an equal
amount of offset to the pixel values from each channel. The offset balance settings let you
individually adjust the offset applied to the left half and to the right half of the sensor. They also
allow you to adjust the offset applied to the odd pixels and the even pixels in each half of the
sensor. As a group, these settings let you adjust the sensor’s “offset balance.”
Left/Right Offset Balance
When the camera is set for 8 bit output, the left/right offset balance is adjustable within a range
from -20.0 DN to +20.0 DN (digital numbers) in increments of 0.5 DN. When the camera is set for
10 bit output, the range is from -80.0 to +80.0 DN and is adjustable in 0.5 DN increments.The
default setting is 0 DN.
Setting the offset balance to a positive number will increase the offset applied to the pixel values
from the left half of the sensor and decrease the offset applied to the pixel values from the right
half. Setting the offset balance to a negative number will decrease the offset applied to the pixel
values from the left half of the sensor and increase the offset applied to the pixel values from the
right half.
As an example, assume that you have set the global offset on the camera to +10.0 DN and the
offset balance to +1.0 DN. In this case, the camera would be operating with a +11.0 DN offset for
the left half of the sensor and a +9.0 DN offset for the right half.