Glossary
Here are some terms that we will be using over the quarter. I recommend that you continue your research using sites such as Wikipedia and techterms.com.
Video Terms…………………………………..
Aspect ratio – The shape of a TV screen expressed in height compared to width. Older TV screens have a 4:3 aspect ratio, newer monitors are widescreen, 16:9.
CCD – Charge coupled device, a popular type of image sensing pickup chip in TV cameras.
Codec – Coder-Decoder, an electronic device devoted to compressing and decompressing video.
Compression - Process for storing digital data in a smaller space than it would normally take. A 2:1 compression would squeeze the data into half its original size. [5]
Digital Video Camera - A camera that does not take analog video; digital video cameras can capture truer color and more details than analog cameras. Digital cameras frequently use digital video tapes, internal hard drives or memory cards. Digital video is not always high-definition.
HDV - A relatively inexpensive high-definition video recording format.
MiniDV tape - a small format digital video cassette.
.mov – A video publishing format associated with Apple’s QuickTime.
Non-linear editing – Assembling video sequences that are randomly accessible, typically digitized onto a hard drive. The process is much like word processing in that items can be moved, deleted, copied, or changed electronically before being printed or copied to video tape. [12]
standard definition (SD) - For years, this was the common video quality for broadcast television; most television is moving to higher-definition quality video.
Digital Audio Terms…………………………………..
Analog-to-Digital (A/D) Converter - A circuit that converts an analog audio signal into a stream of digital data (bit stream).
Bit depth - In digital audio, bit depth describes the potential accuracy of a particular piece of hardware or software that processes audio data. In general, the more bits that are available, the more accurate the resulting output from the data being processed.
Decibel (dB) - The unit of measurement of audio level. Ten times the logarithm of the ratio of two power levels. Twenty times the logarithm of the ratio of two voltages.
Destructive Editing - In a digital audio workstation, editing that rewrites the data on disk. A destructive edit cannot be undone.
Digital Audio – An encoding of an analog audio signal in the form of binary digits (ones and zeros).
Distortion – An unwanted change in the audio waveform, causing a raspy or gritty sound quality. The appearance of frequencies in a device’s output signal that were not in the input signal. Distortion is caused by recording at too high a level, improper mixer settings, components failing, or vacuum tubes distorting.
Frequency - The number of cycles per second of a sound wave or an audio signal, measured in hertz (Hz). A low frequency (for example, 100 Hz) has a low pitch; a high frequency (for example, 10,000 Hz) has a high pitch.
Level - The degree of intensity of an audio signal–the voltage, power, or sound pressure level. The original definition of level is the power in watts.
Microphone - A type of transducer, a device which converts energy from one form to another. Microphones convert acoustical energy (sound waves) into electrical energy (the audio signal).
Mono, Monaural – or monophonic sound reproduction is single-channel. Typically there is only one microphone, one loudspeaker, or (in the case of headphones and multiple loudspeakers) channels are fed from a common signal path.
Peak – On a graph of a sound wave or signal, the highest point in the waveform. The point of greatest voltage or sound pressure in a cycle.
Phantom Power - A DC voltage (usually 12 to 48 volts) applied to microphone signal conductors to power condenser microphones.
Reverberation - Natural reverberation in a room is a series of multiple sound reflections which makes the original sound persist and gradually die away or decay (envelope). For example, reverberation is the sound you hear just after you shout in an empty gymnasium. A reverb effect simulates the sound of a room–a club, auditorium, or concert hall–by generating random multiple echoes that are too numerous and rapid for the ear to resolve. The timing of the echoes is random, and the echoes increase in number with time as they decay. An echo is a discrete repetition of a sound; reverberation is a continuous fade-out of sound.
Sampling Rate – Sample rate is the number of samples of audio carried per second, measured in Hz or kHz (one kHz being 1 000 Hz). For example, 44 100 samples per second can be expressed as either 44 100 Hz, or 44.1 kHz.
Stereo, Stereophonic - An audio recording and reproduction system with correlated information between two channels (usually discrete channels), and meant to be heard over two or more loudspeakers to give the illusion of sound-source localization and depth.
Photography Terms…………………………………..
Aperture – The adjustable opening in a camera lens used to control the amount of light reaching the film. The size of this hole is called the f-stop.
Aperture Priority – An exposure mode on an automatic or autofocus camera that lets you set the aperture while the camera sets the shutter speed for proper exposure. If you change the aperture, or the light level changes, the shutter speed changes automatically.
Autofocus (AF) – System by which the camera lens automatically focuses the image of a selected part of the picture subject.
CCD – Charge Coupled Device: one of the two main types of image sensors used in digital cameras. When a picture is taken, the CCD is struck by light coming through the camera’s lens. Each of the thousands or millions of tiny pixels that make up the CCD convert this light into electrons. The number of electrons, usually described as the pixel’s accumulated charge, is measured, then converted to a digital value. This last step occurs outside the CCD, in a camera component called an analog-to-digital converter.
Depth of Field – The amount of distance between the nearest and farthest objects that appear in acceptably sharp focus in a photograph. Depth of field depends on the lens opening, the focal length of the lens, and the distance from the lens to the subject.
Depth of Focus – The distance range over which the film could be shifted at the film plane inside the camera and still have the subject appear in sharp focus; often misused to mean depth of field.
DPI – Dots per inch: A measurement of the resolution of a digital photo or digital device, including digital cameras and printers. The higher the number, the greater the resolution.
Exposure – The quantity of light allowed to act on a photographic material; a product of the intensity (controlled by the lens opening) and the duration (controlled by the shutter speed or enlarging time) of light striking the film or paper.
Film Speed – The sensitivity of a given film to light, indicated by a number such as ISO 200. The higher the number, the more sensitive or faster the film. Note: ISO stands for International Standards Organization.
f-Stop – A number that indicates the size of the lens opening on an adjustable camera. The common f-numbers are f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, and f/22. The larger the f-number, the smaller the lens opening. In this series, f/1.4 is the largest lens opening and f/22 is the smallest. Also called f-stops, they work in conjunction with shutter speeds to indicate exposure settings.
Focus – Adjustment of the distance setting on a lens to define the subject sharply.
Histogram – A graphic representation of the range of tones from dark to light in a photo. Some digital cameras include a histogram feature that enables a precise check on the exposure of the photo.
ISO Speed – A rating of a film’s sensitivity to light. Though digital cameras don’t use film, they have adopted the same rating system for describing the sensitivity of the camera’s imaging sensor. Digital cameras often include a control for adjusting the ISO speed; some will adjust it automatically depending on the lighting conditions, adjusting it upwards as the available light dims. Generally, as ISO speed climbs, image quality drops.
IS – Stands for “Image Stabilizer”. This is available in some Canon EF lenses and compensates for camera shake allowing slower shutter speeds.
Megapixel - Equal to one million pixels.
Shutter - Blades, a curtain, plate, or some other movable cover in a camera that controls the time during which light reaches the film.
Shutter speed – The camera’s shutter speed is a measurement of how long its shutter remains open as the picture is taken. The slower the shutter speed, the longer the exposure time. When the shutter speed is set to 1/125 or simply 125, this means that the shutter will be open for exactly 1/125th of one second. The shutter speed and aperture together control the total amount of light reaching the sensor. Some digital cameras have a shutter priority mode that allows you to set the shutter speed to your liking. See also aperture.
Shutter Priority – An exposure mode on an automatic or autofocus camera that lets you select the desired shutter speed; the camera sets the aperture for proper exposure. If you change the shutter speed, or the light level changes, the camera adjusts the aperture automatically.
White balance – A function on the camera to compensate for different colors of light being emitted by different light sources.
Macintosh Terms…………………………………..
OS – Operating System. Software that coordinates the internal activities of the computer and its peripheral devices. An operating system performs basic tasks such as moving data to and from devices and managing information in memory.
CPU –Stands for “Central Processing Unit.” This is the pretty much the brain of your computer. It processes everything from basic instructions to complex functions. The CPU can also be referred to simply as the “processor.”
Hardrive – The hard drive is what stores all your data. It houses the hard disk, where all your files and folders are physically located. A typical hard drive is only slightly larger than your hand, yet can hold over 100 GB of data. The data is stored on a stack of disks that are mounted inside a solid encasement. These disks spin extremely fast (typically at either 5400 or 7200 RPM) so that data can be accessed immediately from anywhere on the drive. The data is stored on the hard drive magnetically, so it stays on the drive even after the power supply is turned off.
The term “hard drive” is actually short for “hard disk drive.” The term “hard disk” refers to the actual disks inside the drive. However, all three of these terms are usually seen as referring to the same thing — the place where your data is stored. Since I use the term “hard drive” most often, that is the correct one to use.
RAM – Stands for “Random Access Memory,” and is pronounced like the male sheep. RAM is made up of small memory chips that form a memory module. These modules are installed in the RAM slots on the motherboard of your computer.
Every time you open a program, it gets loaded from the hard drive into the RAM. This is because reading data from the RAM is much faster than reading data from the hard drive. Running programs from the RAM of the computer allows them to function without any lag time. The more RAM your computer has, the more data can be loaded from the hard drive into the RAM, which can effectively speed up your computer. In fact, adding RAM can be more beneficial to your computer’s performance than upgrading the CPU.
Motherboard – The motherboard is the main circuit board of your computer and is also known as the mainboard or logic board. If you ever open your computer, the biggest piece of silicon you see is the motherboard. Attached to the motherboard, you’ll find the CPU, ROM, memory RAM expansion slots, PCI slots, and USB ports. It also includes controllers for devices like the hard drive, DVD drive, keyboard, and mouse. Basically, the motherboard is what makes everything in your computer work together.
File Size – The length of a file in bytes. See “Byte Specifications” in the term byte.
Kilobyte – KB A unit of computer memory or data storage capacity equal to 1,024 (210) bytes. Common files – email, text document.
Megabyte – MB
1024 kilobytes. Common files – still images, higher quality audio files.
Gigabyte – GB
1024 megabytes. Common files – standard definition video files.
Terabyte – TB
1024 gigabytes. Common files – Long HD video files.
USB – Universal Serial Bus (USB)
A plug and play interface between a computer and add-on devices (such as printers, scanners, digital cameras, keyboards, mice, etc.)
USB Drive – A small, portable flash memory card that plugs into a computer’s USB port and functions as a portable hard drive. USB flash drives are touted as being easy-to-use as they are small enough to be carried in a pocket and can plug into any computer with a USB drive. USB flash drives have less storage capacity than an external hard drive, but they are smaller and more durable because they do not contain any internal moving parts. USB flash drives also are called thumb drives, jump drives, pen drives, key drives, tokens, or simply USB drives.
Firewire – IEEE 1394
High-speed interface is a standard for connecting peripherals such as digital video cameras, hard drives, audio interfaces, and MP3 players, such as the Apple iPod, to your computers. This allows for quick transfers of large video files, which is great for video-editing professionals. If 400 Mbps is still not fast enough, Apple Computer released new PowerMacs with Firewire 800 ports in early 2003. These ports support data transfer rates of 800 Mbps — twice the speed of the original Firewire standard.
Network – Put simply, networking is a connection between at least two computers so they can share resources. All networks are based on the concept of sharing.
Devices that are often networked: computers, servers, printers, routers, switches
Communication channels: cable and phone lines and satellites, using copper wires, fiber optic cable, radio waves and infrared.
Networks can link users that are in the same office, or on different continents.
The largest network is the Internet
File Server – A computer attached to a network that has the primary purpose of providing a location for the shared storage of computer files (such as documents, sound files, photographs, movies, images, databases, etc.) that can be accessed by the workstations that are attached to the computer network.
Ethernet – A family of frame-based computer networking technologies for local area networks (LANs). The name comes from the physical concept of the ether. It defines a number of wiring and signaling standards for the Physical Layer of the OSI networking model, through means of network access at the Media Access Control protocol (a sub-layer of Data Link Layer), and a common addressing format.
