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close this book Audio-Visual Communication Handbook
close this folder Presentation methods and materials
View the document Demonstrations
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View the document Projected materials
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Projected materials

Because a bright light stands out in darkened surroundings, projected materials often capture the exclusive attention of an audience. Therefore, they generally have great appeal. Because of their appeal, properly produced materials may promote acceptance of new ideas or practices that are presented by slides, filmstrips and motion pictures, or by projecting photographs or drawings with opaque or overhead projectors.


When using projected materials, avoid those in which the pacing is too rapid and those. with complex production techniques (cutaway drawings, slow motion, fades and dissolves, flashbacks, etc.). A simple, straightforward presentation, culturally appropriate, can compel attention, and can present a process or describe a situation in ways that will be easily understood. The best way to secure materials appropriate for an intended audience is to make them, even though electric power, cameras and projection equipment, and some production skills will be needed.

There are advantages and disadvantages to using several varieties of projected materials, and some general considerations of projection applicable to projected materials should serve as guidelines for selecting the medium.


A single slide or carefully planned slide sequence, accompanied by narration, can be one of the most useful projected materials. When using slides in a village or school where electrical power is not available, projectors can be obtained that operate on a variety of voltages. Some are designed to be used with automobile batteries or small generators coupled to a bicycle. Several flashlight-type projectors have been developed that project a reasonably bright image about 3 x 4 feet in size. It is possible to construct a slide projector from wood or sheet metal and a few optical and electrical parts. Plans for two such projectors are included in Appendix 5.


Before making slides, check the kind of slide projector available. Slides come in a variety of sizes ranging from approximately ¾" X 1" to 3¼" x 4". The most common slide is called the 2 by 2. This refers to the slide mount and actually includes a number of different image sizes. The four most common are shown below.

135 - 35 mm


135 - Half Frame

127 - Super-Slide (38x38 mm), 828 - (26.2x38 mm)

Handmade Slides

There are many occasions when a title slide or a slide with a simple illustration or perhaps 8 few words is needed. There are several ways that such slides can be made with materials that are readily available in most places.

- Scratch the image with an awl or needle on a piece of black and white film that has been exposed and developed. The unexposed ends of color film can be used in a similar manner.

- Use fine point, felt-point pens on clear photographic film, acetate, or plastic sheeting. The ink in some pens works well; others tend to run. Check what is available locally and make a few tests to see what combination of ink and base works best. India ink and most colored inks will run on clear acetate; however, art stores usually sell treated acetate that will accept ink.

- Ink or colored pencils can be used on acetate that has a frosted or matte surface. A transparency made on matte acetate should be sprayed with clear plastic or dipped in lacquer to increase its brightness when projected.

- It a thermal or heat copier is available, it can be used to make high quality slides. Thermal copiers are available at some Peace Corps offices and some schools in larger cities. Thermal copying is described in detail in the next section under duplication.

One of the advantages of using handmade slides is that they are not restricted to standard film sizes. Slides can be made the size of super slides or any other shape and size that will tit in a 2 by 2 mount. Handmade slides are ideal for use with larger projectors such as a 3¼. by 4 lantern slide projector. Slide mounts can be purchased or made from thin cardboard.

Photographic Slides


Many inexpensive cameras are available which will make good quality color slides for teaching purposes. When planning such slides, consider the following:

- Choose a camera and accessories that will meet your needs. A camera in the $30 to $50 range can be used for most outdoor photography including distances as close as two or three feet and indoors with flash. Closeup attachments are available for copying. Generally speaking, single-lens reflex cameras are best for copying and for closeup photography. They can be focused as close as 12 to 14 inches, and the viewfinder shows almost exactly what will be in the final picture. Single-lens reflex cameras generally cost $150 or more, but are well worth the money if extensive closeup photography is planned, and it you are willing to take the time needed to learn to operate the camera properly. Before buying any camera, consult a qualified dealer for information about the kind of equipment to meet the need.

- Learn to use the camera properly. The starting point is to study the instruction book. There are several good booklets on slide making available from the Eastman Kodak Company. Study them carefully to improve pictures.


- Choose the right film. A wide variety of color films are available. Some are designed for indoor use, some for outdoors, and some for poor lighting conditions or "high speed" photography.

Choice of film depends on the job to be done, availability, and personal preference. Technical facilities and expertise are needed to process color film, so the selection of a color film should also be based on the availability of good, reliable commercial processing within the country or on a reliable mailing service. If unsure about film selection, start with a medium speed outdoor color film that will serve most needs. Such films are designed for use in daylight, but can be used indoors with blue flashbulbs.


- Strive for good technical quality. Focus carefully, avoid obstructing the lens with a finger or part of the camera case, hold the camera steady, and expose correctly. Many new cameras set exposure automatically. If adjustments must be made manually, following the guide on the film instruction sheet will insure consistently well-exposed pictures. Remember that a very light scene, such as a white house surrounded by sand or a light-skinned person dressed in light-colored clothing, will require less exposure than an average subject. Conversely, a dark subject such as a dark-skinned person against a background of foliage will require more exposure than an average subject.

Take pictures of a variety of subjects under different lighting conditions. Keep a record of exposures and carefully observe the results to provide a good guide to future picture exposure problems.

- Compose the picture carefully. More important than technical quality is how the subject is treated. First, decide what the subject will be doing. A farmer can be digging, planting, fertilizing, wiping his brow, or just standing posing. Keep the pictures active; the posed picture does little to convey the idea of a farmer's work. Second, keep it simple. Many otherwise good pictures are spoiled by poles or trees growing out of people's heads or persons or buildings in the background. Extraneous details that detract from the message should be eliminated. If the background is irrelevant, move in and shoot a closeup. When shooting flash pictures indoors, it is particularly important to watch for distracting reflections from shiny background objects. Unless slides are to be viewed by visually sophisticated audiences, shoot from a familiar angle. High or low viewpoints and odd angles are not always understood by the viewer.

Suggested Applications

To make a permanent visual comparison of a fertilization demonstration plot.

To teach a step-by-step process such as repairing a hole in a road, planting a garden, or processing fish.

To supplement a commercial filmstrip with locally made pictures.

To record the activities at an agriculture or health show as a guide for planning later shows.

To document bulletin boards or other displays as a guide for putting up similar displays at a later date.

To tell a story relating to nutrition, the values of using quality seed, cleanliness, etc. Handmade slides with simple characters scratched or drawn on acetate can be very effective. Flannel board presentations photographed in a step-by-step sequence are also good for this same purpose.


To record school or village activities as a guide for your successors.

To record geological features in the surrounding countryside as a local supplement to a textbook.

To tell the story of a farm or industry that will be visited on a field trip. Such slides can be used before a trip to orient the audience or later as part of a discussion of what was seen.

To motivate the audience by showing other villagers actively engaged in similar projects.

Evaluation Questions

Were the slides carefully planned?

Could they have been organized in a more effective way?

Did distracting elements get in the way of the message?

Could the audience understand each photograph or drawing?

Were the objectives met?

Could members of the audience actually perform the steps of repairing a hole in the road?

Could they state the steps necessary to plant a garden?

Could they repeat the key points in a nutrition story?


A filmstrip is a series of pictures on one continuous piece of film. Although filmstrips lose the flexibility of slide sets (which can easily be rearranged for different purposes), they do have some real advantages. Filmstrips can be carefully sequenced and the sequence will remain unchanged no matter who uses the strip. Once a filmstrip has been threaded properly, all the frames will appear in proper position. Filmstrips are compact, and one small can will hold the equivalent of several dozen slides. The cans are convenient for storage and mailing. Filmstrips on nearly every subject are available from commercial suppliers; and, in many countries, are available through central agencies such as the ministries of agriculture, education or health.

Most commercial filmstrips are made with a single-frame camera. However, double-frame filmstrips can be made by using a double-frame camera. The diagrams show examples of both kinds. Which is used depends on the kind of camera and projection equipment available.

Single frame filmstrip

Double frame filmstrip

To make filmstrips, keep the following ideas in mind:

- Plan carefully. The individual frames cannot easily be rearranged after shooting, so plan the sequence of pictures carefully and then follow the plan exactly. Following the steps of preparing a content outline, a treatment, and storyboard-script, as illustrated in Appendix 1, can help assure a well-organized final product.

- Consider a variety of production techniques. A filmstrip can be made by shooting a series of live action scenes or by shooting a series of still photographs, but there are many other alternatives. A puppet presentation or the steps of a flannel board presentation can be photographed. Titles can be interspersed by taking pictures of titles written on a chalkboard or cutout letters on a flannel board or other suitable background. Handmade filmstrips can be made by using one of the processes listed under slidemaking. Try making a series of India ink or soft pencil drawings on a sheet of paper and then copying them with a thermal copier. Several strips of five or six pictures can be Included, and these can then be cut up and taped together to make one continuous strip. This method presents a bit of a projection problem as there are no perforations to guide the film, but such a strip can be pulled through by hand.

Most of the use and evaluation suggestions that apply to slides are also applicable to filmstrips; however, one particular use of filmstrips deserves emphasis.

Filmstrips covering basic processes can be carefully planned and produced so they will be appropriate to large segments of the population. With printed guides about using them, these filmstrips can be distributed to teachers, health workers or extension agents. Such materials can increase the effectiveness of their communication. If recording facilities are available, a filmstrip can be accompanied by a tape narration. A particularly good example is a series of filmstrips on basic life processes, planned by Dr. Gerald Winfield of the U.S.A.I.D. Information about this series is available from the Norwood Studio, 5104 Frolich Lane, Tuxedo, Maryland 20781. Below is a sample of a few frames from one of these strips.


Motion Pictures

There is little doubt that motion pictures can be extremely effective for teaching in schools or rural villages in developing nations. Motion pictures share one primary attribute of still projection - they compel attention in almost any circumstance.

However, motion picture projectors are expensive to purchase and generally are not readily available. Even if projectors are available, a more critical disadvantage is that films relevant to the problems of a village or a class in the typical schools of developing nations are scarce. Some films would be applicable in formal education classes such as science, geography or mathematics, but these are difficult to obtain and are beyond the budgets of most schools.

If a motion picture projector is available, films can often be obtained from agencies of the United States and other nations as well as ministries of agriculture, education, health and information. These will usually be 16 mm films.

In recent years there has been increased use of 8 mm films. A new format called "super 8" has come onto the market and is being widely used for short, single concept films, film loops, and regular educational films. The super 8 format has resulted in new equipment such as lightweight projectors that thread automatically and self-contained cartridge projectors that combine projector and screen in a unit 9½ inches long, 5½ inches wide, and 7 inches deep. Some projectors will accommodate either regular or super 8 films.

Eight millimeter films have several important advantages for those who want to use films to communicate, but cannot afford 16 mm equipment or films.

1. Short, 8 mm silent cartridge films are relatively inexpensive (average cost about $10), or they can be made by one who is willing to devote some time to learning the fundamentals of planning film sequences and operating a camera.

2. Cartridge films can be used with a minimum of instruction and supervision.

3. Equipment is lightweight and easily transported.


For anyone interested in making films, several publications explain the fundamentals of planning a film story. Camera operation is also discussed in a number of publications; but, in general, the instruction booklet that comes with a camera is adequate for a start toward making good films.

Keep these ideas in mind when choosing and using films.

- Consider the audience when choosing a film. The audience must be able to identify people and scenes, so avoid films that use odd angles and fast pacing. The presentation should be simple and straightforward.

- Preview the film in advance. Viewing a film before showing it to an audience is helpful in introducing it and even in deciding what parts to show. If only parts of the film are applicable, they can be carefully marked during preview by inserting a piece of paper in the reel at the points where the film is to be started and stopped.


- Introduce the film. Before a showing, tell the viewers what the film is about and what they should look for.

- Use proper projection practices. Instruction sheets that come with the equipment and instructions printed on the case or the projector itself usually provide all necessary information. Always set up in advance to be certain that the equipment is working adequately. Keep a spare projection bulb and a spare exciter lamp on hand and know how to change them.


- Discuss the film. Discussion, after a film showing, may be the most important part of the presentation. Ask questions about pertinent parts of the film. Encourage questions from the audience. This provides an opportunity to point up misconceptions or things that were missed.

- Re-show all or part of the film. Re-showing provides the audience an opportunity to grasp more fully the concepts presented and to pick up important details that may have been missed.

- Combine the film showing with other media. Bulletin boards, posters or wall newspapers can be used to announce film showings. A chalkboard, flannel-board or flip chart can be used to list important points when introducing a film or when reviewing it after a showing. Mimeographed handouts can be distributed to the audience as a ready reference to key elements in a film.

Suggested Applications

To attract and focus the attention of a large group on a major campaign or project.

To show the step-by-step progress of a major project such as a road building, irrigation or water supply project.

To document a local event.

To show processes where movement is of particular importance such as the processes of meiosis or mitosis or the operation of a machine.

To demonstrate a process to a large group.

To entertain an audience. Entertainment films are popular all over the world and attract large crowds of people. Such films can be followed by a slide show, a short talk or some other presentation relating to a problem in the areas of agriculture, health, family planning and so on.

Evaluation Questions

Was the film content and style of presentation suitable for the audience?

Could the same ideas have been presented with equal effect by using a simpler and less expensive medium?

Was the projection adequate or were there distracting elements such as unnecessary delays?

Would additional discussion before or after the film have helped the audience understand the ideas being presented?

Opaque Projection


Opaque projectors are available for projecting materials such as maps, photographs, book pages, student papers, or even three-dimensional objects. This is often quicker, more convenient, and safer than handing the materials around the room. Most opaque projectors are large and cumbersome; however, some small projectors are available that are useful for projecting small pictures from a book or magazine onto a piece of paper or cardboard so that it can be traced to make an illustration for a poster chart or flannel board. Opaque projectors require a dark room because they have a low light output compared with projectors which show transparencies.

Overhead Projection

Overhead projectors are used to project large transparencies as well as some opaque and translucent materials. With an overhead projector, the image is projected on the screen behind the teacher. The large transparency size coupled with an efficient illumination and lens system provides a large, bright image on the screen that does not necessitate darkening the room. Some teachers have built their own overhead projectors, but this requires optical and electrical parts and considerable skill. See Appendix 5 for suggestions on making an overhead projector.

A wide variety of materials can be used on an overhead projector in addition to handmade or commercially prepared transparencies. Partially transparent objects, such as a plastic ruler or protractor, project very well and can be used for demonstrations on measuring. Strips of cardboard or thin wood can be fastened together with paper fasteners to make movable joints for demonstrating geometric figures. Gears or other moving parts can be placed on the stage of the projector and moved by hand as their interrelationships are discussed.



There are several techniques for making overhead transparencies including photography, transferring an illustration from a magazine by the lifting process, diazo and thermal processes, and various hated-drawn techniques. Hand-drawn transparencies are the most useful when resources are limited. They can be made on cellophane, clear acetate, or old photographic film that has been cleared in a strong chlorine household bleach. Used film may sound like a scarce item. Old X-ray films are often available from hospitals, and they are ideal. Some translucent materials such as thin tracing paper or matte acetate can be used. Matte acetate looks something like very thin tracing paper and is available in most art supply stores. Lettering or drawing can be done with waxed pencils, India ink, colored drawing inks, and some felt-point pens. See what is available locally and make some tests to find what will work. Transparencies on matte acetate can be made more transparent by spraying with clear plastic spray.

When making and using overhead materials consider these factors:

- Keep it simple. Use one basic idea in each transparency and avoid unnecessary visual elements.

- Use legible lettering. Combine a simple style with careful spacing and be sure the letter size on the transparency is no less than 1/4" high.

- Use imaginative design. This can help attract and hold attention and increase understanding. Overlays can be used over a basic transparency to highlight or point out specific elements.

- Use good projection techniques. Line up the projector and focus in advance. Face the audience and stand to one side of the projector so an arm or shoulder does not block part of the projected image.

Overhead transparencies can be used to help teach a variety of concepts in many subject areas. Evaluation of effectiveness should be based on their contribution to meeting the instructional objectives.

Projection Techniques

There are many factors that can affect the quality of projected images. Three of these are particularly important: the kind of screen; the placement of the audience in relation to the screen; and the size of the image and its brightness in relation to the surroundings. In many situations there is little control over these factors; however, an understanding of them contributes to more effective production and use of instructional materials.

- Screens. Several kinds of commercial screens are available, but for most purposes a piece of white vinyl plastic will provide an adequate screen at a much lower cost. A white vinyl window shade is ideal as it can easily be rolled up for carrying and storage. Satisfactory screens can also be made by painting a piece of hardboard or plywood with flat white paint or by stretching a white sheet on a wall or between two poles.

- Audience placement. The audience will be able to see better if they are not at an extreme angle to the screen. Before a show, look at the projected image from a variety of positions to determine where the audience should sit.

- Image size and brightness. Keep the image size large enough so that it can be seen by all members of the audience. Image brightness can be improved by projecting in a relatively dark place. In a school situation, close the window shutters or put a drape over the window. Any lightweight cloth, reasonably opaque, will work well. If covering the window creates a ventilation problem, place the drapes a few inches from the wall so they cover the window and an area around it, but still allow air to circulate. Place the screen in a spot where a minimum of light from sources other than the projector will reach its surface. Remember that the kind of materials projected affects image brightness. Color pictures or black and white pictures with fine detail require high screen brightness. If simple materials, such as line drawings, words or graphs are used, lower screen brightness will be satisfactory.