Instructional A.V Media and Instructional A.V Media and Educational TechnologyEducational 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- Camera • 2- Monitor

SIMPLE CCTV SYSTEMsline powered

Multi line

SYSTEMS WITH VIDEO RECORDING

Movable cameras

More components for simple CCTV

• Camera

• Monitor

• Video center

• A/V cable