Backlight: A light which is positioned behind the subject. It's primary purpose is to make the subject stand out from the background by highlighting the subject's outline. More info: 3-point lighting
Backlight Correction (BLC): A feature of some cameras which increases the apparent brightness of the subject when lit from the rear.
Back Focus: The focus between the lens and the camera. Adjusted by a ring at the rear of the lens (the closest ring to the camera body). If the camera appears focused when zoomed in, but becomes out of focus when zoomed wide, the back focus needs adjusting. More info: How to focus and how to back-focus
Balanced Audio: An audio signal which consists of two "hot" signals plus the shield. The hot signals are inverted relative to each other as they travel along the balanced cable. They are re-inverted when entering an audio device — this has the effect of inverting any unwanted interference, thus eliminating it. More info: Balanced Audio
Bandpass Filter: A circuit which filters out all but a certain range of frequencies, ie. it allows a certain band of frequencies to pass.
Barn Doors: Metal projections attached to the front of a light, which can be positioned in various ways to control the dispersal of the light.
Batch Capture: The process of capturing multiple video clips automatically. A batch command is set up from the capture software which includes in and out points for each clip.
Baud: Unit of signal speed — the number of signal "bits" per second.
Beta (1): A group of video formats developed by Sony Corporation. Beta, Beta SP, Digital Beta and other variations are all professional television formats. Betamax is a failed consumer version, losing to VHS in the 1980's. More info: The Beta format, The VHS vs Beta War, Beta SP VT
Beta (2): A pre-release version of computer software. Often distributed widely without charge, in order to obtain feedback, identify bugs, and attract customers.
Binary: The "base two number system" which computers use to represent data. It uses only two digits: 0 and 1. Binary code represents information as a series of binary digits (bits). In the table below, binary numbers are shown with their decimal equivalents.
Bit: Binary digit. One piece of binary (digital) information. A description of one of two possible states, e.g. 0 or 1; off or on.
Bitmap: A series of digital image formats, which record colour information for each individual pixel. As a result, the quality is very high, as is the size of the file.
Biscuit: Square/rectangular metal part which screws to the bottom of the camera plate, and allows the plate to attach to the head. The biscuit comes as part of the head's package, whereas the plate comes with the camera. The biscuit is the "interface" between the two, and is designed to attach to any plate, and fit into a corresponding slot on the head. When the head's quick-release mechanism is activated, the biscuit, plate and camera are all released as one. More info: Setting up a camera tripod
Black balance: A camera function which gives a reference to true black. When auto-black balance is activated (by a switch, positioned with the white balance switch), the iris is automatically shut, and the camera adjusts itself to absolute black. More info: Black balance, White balance
Black burst: A composite video signal with no luminance information, but containing everything else present in a normal composite video signal.
Black noise: Usually refers to silence with occasional spikes of audio. Other definitions are also in use but this is the most common. More info: Black noise, Noise colors
Blonde: A term used to describe tungsten lights in the 2Kw range. More info: Blonde Lights
Blue noise: Random noise similar to white noise, except the power density increases 3 dB per octave as the frequency increases. More info: Blue noise, Noise colors
Bluetooth: A wireless data transfer system which allows devices to communicate with each other over short distances, e.g. phones, laptops, etc.
Blu-ray: A high-definition DVD format supported by a group of manufacturers led by Sony. More info: The Blu-ray Format, Blu-ray vs HD-DVD
BNC: A type of video connector common in television production equipment, used to transmit a composite video signal on a 75Ω cable. More info: BNC connectors
Bridge: Another term for A/D converter.
Broadband: A general term to describe an internet connection faster than 56K. Broadband usually means 512K or greater.
Brown noise: Random noise similar to white noise but with more energy at lower frequencies. More info: Brown noise, Noise colors
Bucket: A solid coloured horizontal bar across the bottom of a colour bar test pattern. The most commonly used bucket colour in PAL patterns is red, referred to as a "bucket of blood". More info: Colour bars & test patterns
Burn: The process of recording information to an optical disk (CD or DVD).
Bus: Pathway which a signal passes along. For example, the main output of an audio mixer is referred to as the master bus. More info: Bus
Buzz Track: A recording of ambient audio, i.e. the background sound of a scene. More info: Buzz Track, Ambient Audio
Byte: A group of eight binary (digital) bits.