Gain Response: Skim And High Gain Modes - Dalsa 1M28-SA User Manual

1M28, 1M75, and 1M150 User's Manual

1.7 Gain Response: Skim and High Gain Modes

The cameras feature two gain options: Camera Gain and Skimming Gain.
Camera Gain (Highgain)
A preprogrammed off-chip amplification of either 1x or 4x gain before AD conversion can be
applied. This gain allows one to get more information out of sparsely illuminated scenes, or
increases the spread of gray levels when using strong logarithmic compression.
Skimming Gain
This gain can amplify small signal levels before readout, thereby increasing sensitivity before
readout noise adds to the signal. Due to the thermally generated leakage current, this gain is only
suitable for relatively short exposure times (<10ms) since it significantly increases the FPN created
by thermal current. The skimming gain can be combined with LinLog response, though the LinLog
transition parameters have to be chosen carefully to prevent blackout of the sensor. The skimming
gain should not be used with very short exposure periods (ie. <10ms), since it has a slightly
increased time constant.
Both gains can be combined, though this increases FPN significantly and usually requires you to
recalibrate the black level.
Figure 11: Skimming Gain and Camera Gain
Signal
Note: In skimming mode increased responsivity results in a nonlinear output.
Note: Gain values are set using the PFRemote configuration tool. See chapter 3 for details on
using the PFRemote.
DALSA
PRELIMINARY
Camera
Sensor
Skimming Gain
1x or 4x
Camera Gain
1x or 4x
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03-32-00525-04