Understanding How Advanced Shutter Settings Improve
The camera dome supports the ability to view color images from extremely
When the Open Shutter is enabled and the scene illumination is too low to obtain a clear image at the normal video rate, the camera collects luminance information from multiple fields. As it does so, the current video information is retransmitted until new information is available from the camera. Under these conditions, moving objects will appear blurred, and still images may appear blurred, choppy, and with more static than video obtained under normal lighting conditions.
The Shutter Limit value sets the video update time in fractions of a second. Depending on the lighting conditions, the video information may be updated more frequently, but no slower than the limit set.
Figure
Figure
Red Light | Red Light | Red Light | Green Light |
250 | 250 |
| 180 |
msec | msec |
| 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
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 lit simultaneously. This situation is illustrated in Figure
Figure
Red Light | Red Light | Red/Green Light | Green Light |
250 | 125 |
| 125 |
msec | msec |
| msec |
Adjusting the Shutter Limit sets the update time used to maintain the image quality. If you want to videotape an incident in
SpeedDome Ultra VII Operator's Manual |