Gain Settings In More Detail; Offset Settings In More Detail - Basler A500k User Manual

Basic Operation and Features

3.7.1 Gain Settings in More Detail

The optical gain Gopt is the digital number value (DN) that the camera outputs after an exposure
with the amount of light of 1 Lux per second. For this camera, the optical gain can be calculated
as follows (formula based on data from sensor data sheet):
If you know the optical amplification you want to achieve, and need to know the Gain register
setting, use the following formula (data based on sensor data sheet):
Some sample values calculated with these formula are listed below:
• If the Gain register is set to 98 (recommended), the optical gain Gopt is 400 DN / lx s (if dig-
ital shift = 0). Gopt can vary slightly between different cameras.
• If the Gain register is set to 196, the optical gain Gopt is 800 DN / lx s (if digital shift = 0).
Gopt can vary between different cameras. The value corresponds to a gain factor of two
compared to the gain achieved with a gain register setting of 98. This is the maximum gain
we recommend.
Note that the calculated values are typical values which can vary slightly between
different cameras.
If the gain you selected is too high, the image will show pixelwise/columnwise miss-
ing codes. We recommend that you do not use gain register values higher than 196.
If youwish to increase the gain further, select the next higher digital shift value and
reset the gain register value to 98.
If the gain you selected is too low, the image will show pixel saturation.
With a digital shift of 1, the optical gain must be multiplied by 2. With a digital shift of 2, the optical
gain must be multiplied by 4. See section 3.8.

3.7.2 Offset Settings in More Detail

The offset can be trimmed in two directions by using either the OfsPos register that moves the
offset up, or by using the OfsNeg register that moves the offset down. If you move the offset down,
set the OfsPos register to 0. If you move the offset up, set the OfsNeg register to 0.
3-30
PRELIMINARY
1.6 DN / lx s
Gopt = ----------------------------------------------------------------------------- -
0.006 0.0000203125 –
Gain register = 295.38 –
×
Gain
1.6 DN / lx s
-------------------------------------------------------- -
×
0.0000203125 Gopt
k
Basler A500