Bosch VG4-200 - Manual (Page 60)

56 en | Glossary of CCTV Terms AutoDome Modular Camera System
F01U064036 | 1.0 | 2007.01 VG4-200, VG4-300, VG4-500i Series User’s Manual Bosch Security Systems, Inc.
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.
Focal Length
The distance from the optical center of the lens to the image of an object located at an infinite
distance from the lens. Long focal lengths give a small field of view (e.g. telephoto effect),
while short focal lengths give a wide angle view.
F-Number
The standard measure of the lens aperture, which is the iris diameter, divided by the focal
length of the lens. The lower the maximum aperture (or F-Number), the more light that passes
through the lens.
F-Stop
See F-Number.
G
Gateway Address
A node on a network that serves as an entrance to another network.
Guard Tour
Allows recorded tours with a combined duration of 15 minutes. Recorded tours consist of
control commands and can be played back as needed. All camera position information is
stored for maximum flexibility (including pan, tilt, zoom, etc.).
H
Hybrid Streaming
The ability to simultaneously stream IP video across a local or wide area network, and CVBS
video via coaxial or fiber optic cabling.