Cameras are focused by moving the image sensor in relationship with the lens, which enables differing back focal lengths for the lens. This adjustment is called Back Focus and is important when fitting a zoom.
Backlash (measured in degrees) is when a camera’s Pan Tilt head cannot stop instantaneously, and is usually caused by excessive looseness in gears, pulleys, or other parts. Pre set PTZ surveillance cameras are rendered ineffectual by Backlash.
That portion of the composite picture signal which lies between the trailing edge of the horizontal sync pulse and the trailing edge of the corresponding blanking pulse.
This stands for Balanced – Unbalanced. Physically, a Balun is a small transformer used to convert audio, video, or VGA signals from balanced to unbalanced, and vice versa. Its practical use is in creating required impedance adjustments for signal transmission between differing wiring systems (like UTP to coaxial cable).
Measured in bps, Bandwidth refers to a telecommunications link’s transmission capacity. The bandwidth available in a connection plays a large role in the speed of an Internet connection. Technically, it is the number of cycles per second (Hertz) expressing the difference between the lower and upper limiting frequencies of a frequency band; also, the width of a band of frequencies.
Bar Test Pattern
Special test pattern for adjusting color TV receivers or color encoders. The upper portion consists of vertical bars of saturated colors and white. The power horizontal bars have black and white areas and I and Q signals.
Biometrics is the technology and science of authenticating individuals by measuring their physiological or behavioral features. In the field of security, they are technologies (‘readers’) used to analyze fingerprints, voice patterns, irises or retinas, etc.
BLC (Back Light Compensation)
Cameras with this feature will automatically bring more detail to darker areas of an image when bright lights (usually shining from behind) obscure it.
This refers to the defocusing and glow present around the bright areas of a picture when the brightness is increased. Some video cameras feature blooming suppression abilities to avoid this.