Video: The Big Picture
Don't judge a book by its video case.
- Julie Larson in The Dinette Set comic strip (23 September 2002)
Whether you're watching television programs, movies, or home-made videos, combining motion images and sounds can bring back memories. When you tell children that in the "olden days" TVs came without remote controls, a "test pattern" played when no programming was available, and in the 1980s people went to a video store to rent videotapes, they may stare at you with horror. The new generation is most familiar with renting DVDs through the mail on instantly on Netflix.
From the Weather Channel to feature films, most children and adults spend time each week watching video. Increasingly, people are finding that video is available from a variety of sources from broadcast television to Internet programming.
A wide variety of videos are available. They can generally be classified into informational, instructional, educational, and entertainment. From travel videos to historical accounts, informational and documentary videos help people gain insights and understandings into a particular topic.
Have you ever wanted to build a birdhouse, plant a garden, or learn to play the piano? Instructional videos are designed to teach specific skills.
From Sesame Street to Creative Writing courses, educational programming is intended to provide learning experiences. Rather than focusing on a specific skill like instructional video, educational programming is flexible enough to be used in many situations.
Entertainment videos are probably the most popular. Including both box-office hits and art-house films, entertainment videos come in a wide range of genres.
For the purposes of this website, video materials are organized into three categories. The first category contains videos you're likely to find at your physical library. The remote collections page explores online collections and the last section focuses on television.
Go to the following sections and read about different types of collections:
- Videotape/DVD Collections
- Remote Collections: Digital Video
Some videos bridge the four categories. For example, Ken Burn's Civil War series is informational, educational, and entertaining. It was originally available on television, but now it can be purchased in both video and DVD. In addition, a website that accompanies the video series contains many additional resources to expand the experience including discussions and classroom activities. You can also purchase the book and audio CD to round out the experience.
Videos can be found in schools, libraries, churches, video stores, and homes around the world. From videotape and DVD to satellite television and Internet streaming, videos can be viewed many different ways.
Video is recognized for assisting classroom teachers in conveying difficult information and subject matter to their students. It can also supplement classrooms that have limited resources by bringing to them events and materials that otherwise would not be possible. At a fundamental level, video can provide students with outside stimulation, broadening their world and extending their commonalities.
Video involves the presentation of images on a screen. It usually includes audio played through some type of speaker system. In the past, the cathode-ray tube was used as a means of viewing video, but recently flat screens and projection systems have become popular ways to view video. The latest innovations are HD and 3D options. In general when people think about video, the traditional television comes to mind. Television is usually thought of as moving pictures accompanied by an audio track. Signals are transported over wire, cable, and/or through the air to be received and displayed on a television receiver.
We first think of television as a technology for displaying motion and sound, but it can also display still images. In fact, television is actually displaying still images all the time, we just can’t see them. Similar to film technology, television receivers display a series of still images in such rapid succession that to our eye it appears as motion. Because television technology is powered by alternating electrical current at 60 cycles per second, television images are formed on the screen at a rate of 1/2 picture per cycle, thereby giving 30 full, still images on the screen per second. We see motion.
For decades, motion pictures were stored on film of different widths such as 70mm, 35mm, 16mm, and 8mm. By the mid 1960s, video recorders were used by television stations. Video cassette players were introduced in the late 1970s and by the early 1980s were commonplace. Videodiscs and laserdiscs were also popular for a while in the 80s and 90s. DVDs gained in popularity in the late 1990s. By the early 2000s some video stores stopped supporting their VHS collections. Physical formats may soon be a thing of the past as people increasingly stream their video selections over the Internet.
For a complete and easy-to-understand explanation of both magnetic and digital video recording, visit How VCRs Work by Marshall Brain (Webpage 1 of 6) and How DVRs Work (Webpage 1 of 8) by James Bickers, both at How Stuff Works.
Videotape. For nearly thirty years, videotape technology dominated the educational video industry. A videotape is a ribbon-like, flexible strip of materials that stores magnetic signals. A videocassette is a plastic box that holds the videotape on two reels. The standard VHS format contains an analog signal. At 230 by 250 horizontal lines, it's low quality compared to digital tape. In addition, the quality of the signal degrades over time as the tape wears. A VCR is used to play the videotapes.
Although there are several videocassette formats such as 8mm and Hi8 have been in use, the most popular for both local production and the distribution of commercial video programming was 1/2" VHS (Video Home System). The primary reason for the VHS videocassette’s widespread use is its affordability. When developed, VHS technology was significantly lower in price than the larger 3/4" U-matic predecessor and also lower priced than its direct competitor, 1/2" Betamax. VHS videocassettes travel at 1.31 inches per second in standard play speed and can store 2 hours of programming on a T-120 tape, 6-hours at the extended play speed. Video is magnetically recorded onto the 1/2" videotape as analog data. While some libraries still have VHS collections, digital video has largely replaced this format.
Laserdiscs. Laserdiscs are an optical technology that store visual and audio information. This information can be accessed through the control panel on the player, a remote control, a bar code reader, or the computer.
Laserdiscs were popular in the late 80s and early 90s, but can still be found in the back rooms of some libraries. Images displayed from a laserdisc are sharper, higher-in-quality than those from videocassette tape, but not as high as DVDs. Laserdiscs do not wear with use and require minimal care and storage consideration.
Laserdiscs are 12 inch platters that can contain text, graphics, color photographs, animated movies, audio, and motion video. They can hold up to 54,000 still images or up to 30 minutes of full motion video and sound on each of their two sides. Most people skipped laserdiscs and moved directly to DVD technology.
DVD. Digital Versatile Disk is the same size and material as a CD. A standard DVD can store up to 133 minutes of high-resolution video with up to eight different languages and 32 languages of subtitles. A double-sided, double layer DVD can hold 17GB of information. DVDs use the MPEG-2 video compression system to encode the movie. These disks can be used on special players or on a computer that contains a DVD drive.
Three formats of DVD are found including DVD-Video, DVD-ROM, and DVD-Audio. You're mostly likely to find DVD-Video just called DVD. The DVD-ROM also contains computer information. For example, some movies can be played on the DVD player, but also contain video games that require a DVD player on a computer. DVD-Audio is a new format with larger storage capacity for music than CD.
People using the computer to record DVDs may use a DVD-RW or DVD-R system. The DVD-RW allows users to rewrite several times, while the DVD-R is used to make a one-session DVD.
The next generation of DVD Video replaced the red-laser technology with the higher-definition blue-laser. These "Blu-ray" discs and players were embraced by some consumers, but others have opted to keep their old DVD players or skip over to streaming video options on the web.
QuickTime. The QuickTime (.mov) format can be displayed within your web browser or in a separate window. Some versions of QuickTime movies are streamed (played and downloaded at the same time). It depends how they were saved.
Real Media. The RealMedia (.ram or .rm) files are streamed and play as they download. As a result, they start playing quickly before the entire video is downloaded. These files are only temporarily stored on the computer, so an Internet connection is needed for viewing.
MPEG. The MPEG (.mpg) format is downloaded to your computer.
Flash. Adobe Flash is a plugin for animation and interactivity. It's used for visual effects, games, and animations. It is also used by many of the popular online video services such as YouTube. Videos on YouTube are streamed through the Adobe Flash player. However YouTube is now offering a no-flash HTML5 video option for Chrome and Safari browsers.
Create your own set of FAQs or glossary on DVD technology for your situation.
A number of video distribution systems are used to bring programming into homes, schools, and libraries including local and remote access.
Local Access. A local collection may contain videotapes, laserdiscs, DVDs, as well as digital media stored on computers. Some items, like the classic movie The Graduate, are available in all these formats.
The tapes, discs, or digital files are shown using players hooked to television sets or computer monitors.
Remote Access. Increasingly the media is acquired from another location.
Broadcast television is an audio and video transmission sent through the airwaves and received through an antenna and television receiver. It delivers both commercial and noncommercial network programming such as ABC, CBS, NBC, Fox and PBS. Teachers frequently record programs from a network like a news broadcast, a documentary, or popular situation comedy, and use them in their classroom. NOVA and Scientific American Frontiers are two examples of popular science programming that is often used in the classroom. These broadcasts are free to those who are in an areas where they can receive the signal.
Cable television is an audio and video transmission sent through a cable and received through a television. It was first developed to bring broadcast network programming into isolated communities where households were unable to receive television programming. Today, cable systems exist in most areas. In addition to network channels, cable systems provide programming such as Discovery Channel, History Channel, A&E, Family Channel, C-Span, CNN, Nickelodeon, and The Learning Channel. These networks are not available from regional broadcast stations. A basic fee is charged for access to this service. Additional fees are charges for particular channels or packages of programming. Broadband is an extension of this service and provides a combination of television and Internet services.
Satellite television is an audio and video transmission uplinked through a satellite system and received by a satellite dish. Cables and a receiver box connects the dish and the television. Some systems even build-in two-way video communication, by including video origination and uplinking capabilities along with reception capabilities at all sites. The programming for satellite television is similar to cable television. Major network stations are only available to people in qualifying areas. Many home users DirecTV.
Most television programming is offered using an established schedule. Some cable and satellite services offer on-demand programming. Users access a database of programs that can be selected and played based on an expanded schedule or instantly on request.
Increasingly users are incorporating DVR (digital video recording) options into their packages allowing them to record programming for later viewing.
Closed circuit television (CCTV) and local area networks systems are small, wire or fiber optic cable distribution systems within a single building or within buildings of an institution or an organization. CCTV systems are not government licensed; they are unregulated. Schools often use their own CCTV network to carry programming to classrooms throughout their buildings.
Microwave transmission is used to share programming in some areas. Use of these systems is limited to close geographic regions. Line-of-sight can usually reach about thirty miles or requires the combining or linking of systems to expand to wider distribution areas.
Compressed video is sent of over standard phone lines or special data lines to teach lessons or entire courses. In the past, the term "distance education" was equated with this type of live, two-way audio/video learning. However the use of web-based services has reduced the popularity of these systems.
Web-cast provides voice, video, and data over a network. In the past, video programming on the Web was limited to brief video clips. However with the advent of faster connections, streaming video has become possible. You're probably most familiar with services such as YouTube and Hulu. Whether it's live video conferencing or recorded programming, video over the Internet is becoming popular. The Web’s video limitations are primarily due to the bandwidth limitations of net connections.
Digital distribution companies provide access to subscription services. Some of these services such as OverDrive focus on a wide range of options such as audiobooks, music, and video. Others like Discovery Education are known primarily for their video and educational services. Librarians should check with their regional associations and state representatives to see what services might already be available.
Which of the distribution systems have you used? Which do you see as the systems of the future? Which do you see as part of your "collection"? How do you like local and remote systems will be balanced in the future?
and Limitations of Video Technology
Due to its ease-of-use, affordability, and reliability, video use has become one of the most often-used technologies in the library and classroom. Its fundamental strength is to convey motion sequences. It can bring remote experiences from all over the world and beyond back into the learning environment. Students can visit other countries and study the culture of other peoples. Through reenactments and dramatizations, viewers can be mentally transported into different times and different worlds. The medium can also be used to display fictional events and scenarios that can be used to help learners explore their feelings and attitudes about situations.
Video can be used to spark students to pose solutions to practical and theoretical problems. Through motion, television can display any number of processes, showing the learner exactly how something is done. Learners can be shown a specific skill by an expert. It can give them a close-up, first-hand view, and show them important details as in a microscopic view of cell-life or a surgical procedure. Views from extreme distances can also be shown, such as when a telescopic lens is used to show distant views of another planetary object.
The technology can alter the time frame of events. It can be used to analyze the movements in a tumbler’s somersault by slowing things down (slow motion), or speed events up (time-lapse) in order to watch a butterfly emerge from its cocoon. Animation can be incorporated, altering both time and space, to simulate movement or give movement to inanimate objects. Video can provide a safe observation distance by physically relocating the learner away from potential danger. The viewer can observe an explosive chemistry procedure or travel inside a tornado.
Along with the many strengths of video, there are also a few limitations. For many video distribution systems, the viewer has little useful control over how the material is viewed other than changing the sound level or turning it off. Video and television programming can lead to misinterpretations, either intentional or unintentional. Inaccurate documentary presentations can be taken as absolute. Brief clips can be edited and placed within sequences to give inaccurate representations.
At the classroom level, although some schools have computers and television receivers or some other type of display equipment in every classroom, many teachers have to go through the logistics of scheduling and moving equipment into their classrooms or moving their students to another location for viewing.
The equipment necessary for the reception and recording of video is available at a relatively low price; however, the cost of producing quality programming can also be a limiting factor. Moreover when schools do invest in the needed equipment to do professional production, they are often unable to commit enough people, time and other resources for the effective design and development of quality programming.
In a more technical vein, the video and audio content within most television’s electronic signal is in an analog pattern and its conversion into digital format for computers is a large and complex process. Changing the broad spectrum of visual and audio information of a composite video signal into a series of 1s and 0s for digital technology takes computing time, speed, and space (memory). This limitation has impacted on the converging move of video into the digital technologies.
The Value of Video
From "copycat" crimes associated with movies to accusations that television promotes obesity, some people like to blame video for the problems of society. However rather than focusing on the negatives, let's explore the value of video. The combination of moving images and sounds can inspire, relax, or teach. Watching a feature film may bring a teenager closer to a great grandparent, promote an act of kindness, or inspire a career change.
After watching a movie like Bridget Jones's Diary, a viewer might be inspired to watch other movies based on the ideas found in famous novels. Although reluctant readers might not read Pride and Prejudice, they may watch the movie.