Basler Vision Technologies A202k, User Manual

Page: 44 / 118

Operation and Features
3-14
BASLER A202
k
DRAFT
With binary commands, you must use the Left Side Gain and Right Side Gain binary commands
to set the gain and the Left Side Offset and Right Side Offset binary commands to set the offset.
3.5.1 Setting the Gain
When the gain is set to default, the sensor’s
linear output range directly matches the
input voltage range of the ADCs. Thus, with
the default gain of 0 dB, a gray value of 0 is
produced when the pixels are exposed to no
light and a gray value of 255 (8-bit mode) or
1023 (10-bit mode) is produced when the
pixels are exposed to bright light.
The 0 dB default gain is achieved when gain
is programmed to a decimal value of 288.
(Due to tolerances in the electronic com-
ponents in your camera, you may find that
the 0 dB default gain is achieved with a
slightly different setting.) Increasing the gain
setting to more than 288 maps a smaller
portion of the sensor’s linear output range to
the ADC’s input.
Increasing the gain is useful when at your brightest exposure, a gray value lower than 255 is
reached. For example, if you found that at your brightest exposure your gray values were no
higher than 127, you could increase the gain to 6 dB (amplification factor of 2) and thus reach gray
values of 254 (see Figure 3-11).
Gain is adjustable and can be programmed on a decimal scale that ranges from 288 to 569
(0x0120 to 0x0239). The settings result in the following amplifications:
If you know the decimal number (DN) setting for the gain on your camera, the equivalent decibel
value can be calculated using the following equations:
Decimal Number (DN) Hexadecimal dB Factor
288 0x0120 0 x1
569 0x0239 12 x4
Table 3-1: Gain Settings
Figure 3-11: Gain Settings in dB
Gain in dB 20 log
10
658 DN +
658 DN
–
----------------------------
⎝ ⎠
⎛ ⎞
8.15
–
= When DN setting = 288 ... 511
Gain in dB .0354 (DN) 8.15
–
= When DN setting = 512 ... 569