Post on 29-Dec-2015
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TYPES AND CHARACTERISTICS OF OHP(OVERHEAD PROJECTOR)
PISMP TESL 3 SEMESTER 4
Prepared by, Nur Inani bt Hasim
CONTENT
ITEMS SLIDE NUMBER
Definition 3
Parts of Overhead Projector 4
Examples of Overhead Projector
a) Transmissive Overhead Projector
b) Reflective Overhead Projectorc) Opaque Overhead Projector
567
Features to Choose 8
Types of Transparencies 9
Techniques for the Preparation and
Presentation Transparencies
10, 11, 12, 13,
Transparency Preparation Principles
14, 15
Advantages of OHP 16
Disadvantages of OHP 17
DEFINITION
OVERHEAD PROJECTOR (OHP)
A device that projects an enlarged image of a
transparency placed on it onto a wall or screen by means of an
overhead mirror.
Lets label!
TRANSMISSIVE OVERHEAD PROJECTOR
REFLECTIVE OVERHEAD PROJECTOR
OPAQUE OVERHEAD PROJECTOR
3 FEATURES TO CHOOSE
Lens Type
• Image quality increases as you progress from the basic singlet lens type, to the advanced triplet lens type
Brightness (Lumens)
• 2000 – 2500 lumens (depends)
Lamp life
• Determined by the rating in lumens and lamp type• Generally lasts less than 100 hours• ENX offers the longest lamp lasting period
TYPES OF TRANSPARENCIES
Write-on Thermal (infra-red) Photocopying Ink-jet Film
P/S : Transparency is the medium that is similar to a slide which is classified as teaching aids in the form of projection view.
TECHNIQUES FOR THE PREPARATION AND PRESENTATION TRANSPARENCIES
1. Write-on technique
drawn together by hand or machine directly on transparency film
broadcasted directly to the audience.
2. Window technique several windows that
cover certain parts of the surface of transparencies
When used, the windows will be opened one by one like the home window to display the contents or images.
3. Striped techniques This techniques
have bands either horizontally or vertically
It’s opened only one way not as open windows technique in both directions. Only 3 to 4 strips in a transparency.
4. Overlapping techniques (layered)
Consists of films that are placed directly on the basis of a fixed frame
Some additional film placed on the sides of the frame.
5. Round technique It seeks disclosure of
or part by part to reveal anything needed
It can be made in the cover inserts (vertical, horizontal or diagonal or rounded cap. Spherical cap can be made by means of a pinned in the middle.
6. Animation techniques It uses plastic sheets
polarising fixed upon certain parts of the image that is on the transparencies
during usage, the device is placed on the lens polariser OHP bay. The image will appear to move when the image is pulled or moved.
Overlapping technique
Window technique
TRANSPARENCY PREPARATION PRINCIPLES
Plan appropriate methods or techniques before starting to make transparency with existing equipment.
Analysis of the information to be communicated carefully in terms of use, objectives and content.
Determine the presentation format. Longitudinal or vertical format. Avoid obscure format
Make sure each creation (graphics, statements) are within 2 cm from the edge of the transparent material.
Clarity of alphabets depending on the type, size, spacing between letters and spacing between rows.
The smallest image on the screen should be 2:56 cm in height for every 8 meters distance display.
Use a larger font for headings and sub-headings.
Restrict writing between 6 and 7 lines in a piece of transparency.
Use 7 to 10 words on every sentence.
Advantages of Overhead Projector
Audience reach
User friendlySequence of
materials
Disadvantages of Overhead Projector
Resolution
Problems
Cost to Replace Bulbs
Transportation
Displaying
Material
Outdated Technolo
gy