Dalsa Spyder2 - Optimizing Offset Performance

26 Spyder2 User’s Manual
03-032-10091-06 Teledyne 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:
Sy n t ax :
sao t i
Sy ntax Elements:
t
Tap selection. Allowable values are 1 for one tap or 0 for all
taps. Si nce the Sp y d er 2 is a one tap camera, the val ues 1 or 0
ar e i nter changeable.
i
Analog offset value. Allowable range is
0
to
1023
.
N otes:
• The offset increases linearly with highe
r values. A value of
100 does not equal an offset of 100DN .
•
The resulting analog offset value depends on other camera
parameters such as temperatur e, line rate, and gai n.
•
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:
Sy n t ax :
ssb t i
Sy ntax Elements:
t
Tap selection. Allowable values are 1 for one tap or 0 for all
taps. Si nce the Sp y d er 2 is a one tap camera, the val ues 1 or 0
ar e i nter changeable.
i
Subtracted value in a range fr om
0
to
511
.
N otes:
• When subtracting a digital value from the digital video
signal the output can no longer reach its maxi mum. Use
the
ssg command to correct for this. See section 3.13
Set ting Gains
for details on the
ssg
command.
Example:
ssb 0 20