| Tools for teaching - A visual aids workshop, and instruction manual for health educators |
|Session 1. Introduction to the visual aids workshop|
|Handout 1.8.1 Making & using visual aids (Supplementary learning materials)|
To make a slide presentation:
1) Choose your topic. Write a statement of what it is you want to say. Keep your message brief, simple, and to the point.
2) Think about how you will develop your story/presentation.
• List each step in sequence.
• Follow the sequence steps to write a sample script for the story/presentation.
• Conceptualize a visual image to demonstrate or describe each step.
• Make a storyboard. This can be done on paper or on separate 3" x 5" cards.
NOTE: The more specific you can be with respect to your visual images, the easier it will be to take the necessary photographs.
3) Pretest your idea. Show your storyboard to your family, your friends, your professional colleagues, Pay attention to their suggestions. Refine and modify your idea accordingly.
4) Prepare the slides.
• Use 35 mm. film for colored slides.
Fast film (ASA rating above 2001
e.g. Ektachrome 400
Subject is moving fast
flash close up
Slow film (ASA rating below 200)
e.g. Kodachrome 64
In direct sunlight
In well-lighted place
With close-up flash
(7 - 10 feet)
• Know how to use your camera.
Shutter speed: The camera's shutter opens and closes to let light reach the film. By changing the length of time that the shutter is open, you can control how much light reaches the film. Speed choices on better cameras usually range between 1 second and 1/1000 second. Use a tripod or steady the camera against a firm surface for shutter speeds slower than 1/125 second.
THE POOR MAN'S TRIPOD
If you don't have a tripod and can't find a steady surface to rest the camera on, use the "poor man's tripod".
Tie the ends of a long piece of string together. Attach it to a doorknob or window latch, loop it over the camera and under one foot. Stand far enough away from the wall to exert firm tension on the string.
Focus: Be sure that your subject is in focus. Look through the viewfinder. If the object you are trying to photograph is blurred
rotate the focus ring located on the lens until the image appears sharp and clear.
Aperture (F/stops): Adjustable cameras let you control the amount of light that reaches the film by varying the size of the hole through which the light passes.
The higher the F/stop number, the smaller the aperture.
A high F/stop (small aperture) provides the greatest depth of field. Everything in your picture, both in front of and behind the subject, will be in focus.
With a low F/stop (large aperture), only the object on which you are focusing will appear sharp. The rest of the image may be slightly blurred.
Exposure: Every scene or subject being photographed is lighted, either naturally or artificially, to produce areas of shadows and highlights with a whole range of tones in between. Most 35 mm. cameras have built-in light meters which, when set to the ASA number of the film, can measure the available light and tell you what combination of aperture (how much light) and shutter speed (how long to let it in) to use for an accurate exposure.
In most situations, select the shutter speed first. Then adjust the aperture ring until the needle in the viewfinder indicates that the exposure is correct.
Where depth of field (clarity of the total image) is the primary concern, select the F/stop first and adjust the shutter speed accordingly.
Plan your pictures thoughtfully. Consider both lighting and composition.
Lighting: Before pushing the shutter release, check to be sure that the light falls well on the faces of people and on the details of the scene you are trying to photograph.
Whenever possible, avoid taking outdoor pictures when the sun is high. The harsh light of midday creates dark shadows and "flattens" the image through a loss of detail. It is best to take outdoor pictures an hour or so after sunrise or an hour or two before sunset.
When taking indoor pictures with an artificial light source, you should be aware that fluorescent lighting imposes a greenish tinge to the picture; tungsten light bulbs will result in an orange cast.
To photograph any subject where maximum detail is a priority, (e.g. pictures, charts, skin problems, etc.), use indirect lighting. Outdoors, take pictures on a cloudy or hazy day. Indoors, shine a light against a white wall or sheet so that it reflects onto the subject.
Composition: "Frame" each picture before you shoot. Hold up your hands, thumbs together and forefingers extended...
or make a viewfinder by cutting a 2" x 3" rectangular hole out of a slightly larger piece of cardboard.
Close one eye and move the frame back and forth and from side-to side until you find the most effective composition.
Pay attention to the background. Ask yourself these questions:
Does it add meaning or interest to the main subject of the picture?
Does it add contrast and help the main subject stand out clearly?
Is it free of distraction which might take attention away from the main subject?
Composing a photograph is no different than designing any other visual aid.
State the message clearly and directly.
Include all essential information.
Eliminate all unnecessary elements.
• Take more pictures than you will need.
Don't be caught short when you are putting your presentation together. If you think you might need a particular shot, take it. Nothing says you have to use it in the finished presentation.
IT IS BETTER TO HAVE A PICTURE AND NOT NEED IT THAN TO NEED A PICTURE AND NOT HAVE IT.
Give yourself choices. Photograph the subject from different angles and at different distances. Bracket your exposures. (Shoot the same picture one F/stop higher and one F/stop lower.)
Buy sufficient film. A general rule of thumb is that you will shoot 4 slides for every 1 slide used in the presentation.
When the slides are returned from the processor, be ruthless. Throw away any of them that are not properly exposed or are technically deficient. Poor slides will turn off your audience. Use only your very best.
• Make a title slide.
Prepare the artwork for the title slide on a piece of poster board at least 18" x 24" (46 cm. x 60 cm.). Remember the proportions and format of a 35 mm. slide. Design the title slide accordingly. Allow for sufficient margin around the artwork to permit you to photograph it easily.
Letter the title and any credits that are being included neatly and clearly. For a more professional look, use transfer letters. The use of color and the inclusion of a visual element in addition to the words will make the title slide more dynamic and interesting.
Photograph the artwork. Take the picture outdoors on a cloudy day (see Lighting). Tape or tack the artwork to a vertical surface at eye level. Center the artwork in the viewfinder of the camera making sure that the edges of the poster board are parallel to the frame of the viewfinder. Without shifting the camera's position, step closer to the artwork until the edges of the poster board (as well as the tape or tacks that are holding it to the wall) are no longer visible. Adjust the focus and take the picture. Shoot the artwork more than once by bracketing your exposure. This will help ensure that you get the best possible image. Use a tripod if the shutter speed will be less than 1/125 second.
When you get the title slide back from the processor, check it carefully. If the edges of the board are visible, or if the image is slightly askew, mask off the unwanted areas (or align the image) using thin black plastic tape.
5) Put the presentation together.
• Select the slides to be used in the presentation and number each one in sequence. Pay attention to how a slide is placed in the projector, carousel, or cartridge. Always put the sequence number in the upper right corner facing you as you place the slide in position. That way you will avoid projecting upside-down or backward images.
• Prepare the audio portion of your presentation. If you plan on delivering the presentation "live'', type the narration that accompanies each slide on a separate 3" x 5" card numbered in sequence.
Alternatively, you can tape your presentation. In this case be sure that you pause 3 to 5 seconds each time the projected image is to change.
To deliver the slide presentation:
1) Plan to project the image onto a screen, a blank white wall, or a large piece of poster board stapled to a wooden frame to keep it rigid.
2) Arrange the seating so that the whole audience will have a clear view of the screen.
3) Set up the projector and slides. Check the equipment to be sure everything is in working order. Adjust the focus. If you have taped the verbal presentation, position the tape player convenient to the projector so that you can easily manage both pieces of equipment.
4) When the audience is assembled, introduce the slide show. If possible, darken the room and begin the presentation.
5) Allow time for questions and answers following the presentation. Encourage discussion.