Guppy PRO Technical Manual
V4.1.2
229
When both auto shutter and auto gain are enabled, priority is given to
increasing shutter when brightness decreases. This is done to achieve the best
image quality with lowest noise.
For increasing brightness, priority is given to lowering gain first for the same
purpose.
MinValue and MaxValue limits the range the auto shutter feature is allowed to
use for the regulation process. Both values are initialized with the minimum
and maximum value defined in the standard SHUTTER_INQ register (multiplied
by the current active time base).
If you change the MinValue and/or MaxValue and the new range exceeds the
range defined by the SHUTTER_INQ register, the standard SHUTTER register
will not show correct shutter values. In this case you should read the
EXTENDED_SHUTTER register for the current active shutter time.
Changing the auto shutter range might not affect the regulation, if the
regulation is in a stable condition and no other condition affecting the image
brightness is changed.
If both auto gain and auto shutter are enabled and if the shutter is at its upper
boundary and gain regulation is in progress, increasing the upper auto shutter
boundary has no effect on auto gain/shutter regulation as long as auto gain
regulation is active.
Auto gain control
The table below illustrates the advanced register for auto gain control.
0xF1000368 AUTOSHUTTER_HI
---
[0 to 5]
Reserved
MaxValue
[6 to 31]
Maximum auto shutter value
Note
•
Values can only be changed within the limits of shutter
CSR.
•
Changes in auto exposure register only have an effect
when auto shutter is enabled.
•
Auto exposure limits are: 50 to 205 (SmartView
Ctrl1
tab: Target gray level)
Note
As with the Extended Shutter the value of MinValue and
MaxValue must not be set to a lower value than the minimum
shutter time.
Register
Name
Field
Bit
Description
Table 134: Advanced register: Auto shutter control (continued)
