Instructional A.V Media and Educational Technology Instructional A.V Media and Educational Technology Dr. Antar S. Abdellah

Movie Projector

Movie Projector theory the brain and the retina of the human eye retains an image for a brief moment of time illusion of motion which results when a series of film images is displayed in quick succession At least 16 frames per second (fps) Was famous with Silent films (16-24 fps)

Components Light source Reflector and condenser lens Douser (A metal blade which cuts off light before it can get to the film) Film gate and single image Shutter (gives the illusion of one full frame being replaced exactly on top of another full frame) Imaging lens

components

Types of projectors classified by the size of the film used 8 mm (no sound) Super 8 (Magnetic stripes could be added to carry encoded sound to be added after film development.) 9.5 mm 16 mm (audio-visual ) 35 mm (wide screen movies ) 70 mm (with digital soundtracks)

Sound in movie projectors Analog method (aligned with the frame) optical Digital Dynamic digital Dolby Digital Digital Theatre sound

Language labs

Appearance and configuration a master console (teacher position) student booths (a student tape recorder and headset with a boom arm microphone) The control panel includes: – master playback source equipment (tape recorder), –some means of monitoring of each booth in the class via the teacher headset and –an intercom facility offering 2-way communication between teacher and student

Use and Operation Language labs were important parts in the audio-lingual method Since there were not enough numbers of native speakers around, schools had to depend on language labs for providing Ss with native speaking quality The teacher would normally play a tape, pauses it, Ss repeat, then Ss record parts of the tape, and continue practicing the repetition on their own or at home.

Operation If a student needed help, he could press a call button, the teacher would respond and open a uni-channel with that student A teacher can also stop all Ss ’ tapes and provides instructions or comments to all at the same time. A video can also be played for language training purposes with no facility of Ss copying it.

Problems Language laboratories in the 1970s and 1980s received a bad reputation due to breakdowns No remote control of the tape Poor quality due to overuse No continuous maintenance No supply for new materials Students ’ independency caused many problems

Change In media By the 1980s, the audio-lingual methods was fading out Many schools transformed their old language labs into computer suites With new technologies, old language labs turned into digital language labs (no tape, or recorder, just computers and software.

However New digital labs lack the teacher ’ s control, the needed software, and are mainly used as computer labs rather than for language purposes.

The Closed Circuit

First used in 1942 for recording launching rockets Used widely for safety purposes CCTV 2,200 CCTV systems in Chicago Based on CCTVs, CCDPs (Closed Circuit Digital Photography) are generated Images of the camera scene are transferred automatically to a computer every few seconds Used for monitoring crime, tests, teaching

Problematics Illegal use Personal liberty, Britain is sleepwalking into a surveillance society Developments included high resolution photos, color, linked to databases. Data Protection Acts Special uses: recording UFOs, Big Brother

How people react to CCTVs Generally acceptance but: Some make break them, spray them, focus laser on them or destroy the recorded tapes. CCTVs are very popular in movies.

Other uses Monitoring traffic on a bridge. Recording the inside of a baking oven to find the cause of problems. A temporary system to carry out a traffic survey in a town centre.. Used by the stage manager of a show to see obscured parts of a set. The well-publicised use at football stadiums. Hidden in buses to control vandalism. Recording the birth of a gorilla at a zoo. Making a wildlife program using a large model helicopter. Aerial photography from a hot air balloon. Production control in a factory. Teaching women in KSA

Components 1- Camera2- Monitor

SIMPLE CCTV SYSTEMs line powered

Multi line

SYSTEMS WITH VIDEO RECORDING

Movable cameras

More components for simple CCTV Camera Monitor Video center A/V cable