AutoDome Modular Camera System
Glossary of CCTV Terms | en
79
Bosch Security Systems, Inc.
VG4-200, VG4-300, VG4-500i Series User’s Manual
F01U073308 | 3.0 | 2007.09
D
Day/Night (IR sensitive)
An AutoDome that has normal color operation in situations where there is sufficient
illumination (day conditions), but where the sensitivity can be increased when there is little
light available (night conditions). This is achieved by removing the infrared cut filter required
for good color rendition. The sensitivity can be further enhanced by integrating a number of
frames to increase the signal to the noise ratio of the camera.
Default Shutter
This feature allows the shutter speed to be set to a fast speed to eliminate motion blur and
providing detailed and clear image of fast-moving objects while there is sufficient light. When
light levels fall and other adjustments have been exhausted, the shutter speed reverts to the
standard setting to maintain sensitivity.
Digital Image Stabilization
See Image Stabilization.
DNR
See Dynamic Noise Reduction
Dynamic Noise Reduction
A digital video processing technique that measures the noise (image artifacts) in the picture
and automatically reduces it.
E
Ethernet
The most commonly used local area network (LAN) access method. Ethernet complies with
the IEEE 802.3 standard. The Ethernet standard supports 10 Mbps, 100 Mbps and 1000 Mbps
(Gigabit) data transmission rates.
EnviroDome
AutoDome with environmental protection that allows it to be used outdoors in almost any
climate.
F
Fast Address
A system for setting the address of the AutoDome remotely from the control system.
Fiber Optic Transmission
Refers to the transmission of video and/or data via optical fibers. Optical fibers are thin glass
strands that are designed for light wave transmission. Video and data are digitized and
transformed into a series of light pulses. The use of fiber optics for video and data
transmission offers several advantages over sending electrical signals across copper wires.
First, light pulses are not affected by random radiation in the environment, and thus their
error rate is far lower. Fiber optics span far greater distances without need for repeaters or
signal regenerators, and are far more secure as they are more difficult to tap and taps in the
line can be detected. Optical fiber also provides enormous bandwidth with a single fiber
capable of transmitting trillions of bits per second. There are two primary types of optical
fiber; singlemode and multimode. Singlemode fiber is used when large distances must be
spanned, typically greater than 2 Km/1.2 miles (see Singlemode). Multimode is typically used
to span smaller distances such as the inside of buildings or on small campuses (see
Multimode).
Field of View
The measure of the visible area within the camera’s field of view. The larger the focal length,
the smaller the field of view. The smaller the focal length, the wider the field of view.
