Dalsa Spyder2 S2-1-40 Series, User Manual

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27 Spyder2 User’s Manual
03-32-10091-04 DALSA
3.12 Optimizing Offset Performance
Optimizing offset performance in the analog domain allows you to achieve a better
signal-to-noise ratio (dynamic range) than you would achieve by trying to optimize the
offset in the digital domain.
Setting Analog Offset
To set the analog offset of the camera, use the command:
Syntax:
sao t i
Syntax Elements:
t
Tap selection. Allowable values are
1
for one tap or
0
for all
taps. Since the Spyder2 is a one tap camera, the values 1 or 0
are interchangeable.
i
Analog offset value. Allowable range is
0
to
1023
.
Notes:
•
The offset increases linearly with higher values. A value
of 100 does
not equal an offset of 100DN.
•
The resulting analog offset value depends on other
camera parameters such as temperature, line rate, and
gain.
•
The offset for calibrated and uncalibrated video is set and
saved separately.
Example:
sao 0 200
Subtracting Offset or Background
To subtract the video scene offset or any other background from the output video signal, use the
command:
Syntax:
ssb t i
Syntax Elements:
t
Tap selection. Allowable values are
1
for one tap or
0
for all
taps. Since the Spyder2 is a one tap camera, the values 1 or 0
are interchangeable.
i
Subtracted value in a range from
0
to
511
.
Notes:
•
When subtracting a digital value from the digital video
signal the output can no longer reach its maximum. Use
the
ssg
command to correct for this. See section 3.13
Setting Gains for details on the
ssg
command.
Example:
ssb 0 20