Dalsa Spyder2 S2-2x-04K40, User Manual

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73 Spyder2 4k User’s Manual
03-032-10195-04 DALSA
Appendix D
DC Offset De-rating Curve
This increased dark current is only an issue when the camera is using long integration
times, at the maximum gain setting, or at high ambient temperatures. Operating the
camera at high temperatures or at low line rates with maximum gain, impacts the
camera’s ability to perform offset calibration. Figure 7 illustrates camera operating
conditions and the associated limits for optimal offset calibration. The offset values
indicated are the values obtained after issuing the
cao 0 5
(calibrate analog offset)
command. The plot shows the DC offset over temperature at maximum gain with the
optimal offset calibration limit being represented by the Limit line. The area under the
Limit line shows the operating conditions where the camera’s offset can be calibrated to
camera specifications; the area above the Limit line shows the operating conditions where
the camera’s DC offset is greater than camera specifications. If you are operating the
camera in this range, you may want to reduce the effect of the increased dark current by:
•
Adjusting the calibration target value higher to enable offset compensation to work.
For example,
cao 0 30
.
•
Adding cooling to reduce temperature. Refer to the Thermal Management section on
page 39 for more information.
•
Operating the camera at higher line rate and averaging or discarding the extra lines
Figure 7: Worst Case Calibrated DC Offset vs. Temperature and Exposure Time
1000µs Integration Time 500µs Integration Time 100µs Integration Time