Operator`s manual

3-10 SpeedDome Ultra VI Operator's Manual
Figure 3-5: Graphical view of Shutter Limit settings
180
msec
250
msec
250
msec
In this example, the dome receives information about the color of the traffic light. While the
light is red, the image is relatively static. With the shutter limit set to 1/4 second (250
milliseconds), updated red light information is transmitted at 1/4-second intervals. When the
light changes from red to green, updated light color information becomes available. The dome
must now transmit information about the green light. This update occurs as soon as the green
light information is available. This may occur before the 1/4-second interval elapses. In this
example, the light changed to green after 180-milliseconds. Thereafter the green light
information is transmitted at 1/4-second intervals until new light color information becomes
available.
If the light were to change from red to green halfway through the field integration interval
(125 milliseconds), it may appear that both the red and green lights are on simultaneously.
This situation is illustrated in Figure 3-6.
Figure 3-6: Mixed field integration.
125
msec
250
msec
125
msec
Adjusting the Shutter Limit sets the update time used to maintain the image quality. If you
want to videotape an incident in low-light conditions, you may find that tape quality is not
acceptable. To ensure that the videotape quality is acceptable for possible prosecution
purposes, you may want to test the Shutter Limit settings under the expected lighting
conditions.
The Relationship between IR Mode and AGC and Open Shutter Settings
The current IR Mode setting affects which AGC and Open Shutter settings are available. The
following table lists which AGC/Shutter modes are available based upon the IR Mode setting:
IR Mode Setting AGC Off AGC On Open Shutter
Off
Yes Yes Yes
On
Yes Yes Yes
Auto High
Yes Yes
No
Auto Mid
No No
Yes
Auto Low
No No
Yes
Red Light Red Light Red Light Green Light
Red Light Red Light Red/Green Light Green Light