Optically Projected Aids

you are saying and can result in a loss of continuity. The following principles are involved: . Motivate the audience to want to read the material. . Have a system for smooth distribution. . Maintain contact and continuity. The best time to distribute handouts is at the end of the presentation, during which time you may ask for questions. An alternate time for distribution is before you begin your talk, provided the audience has been previously motivated to recognize the value of the material. OPTICALLY PROJECTED AIDS Optically projected aids include the opaque projector, overhead transparency projector, videotapes (and associated equipment) and the Carousel slide projector. Opaque Projector The opaque projector (fig. 6-5) has two basic applications. First, it can be used to project graphs, photographs and other aids that are too small to be seen but should be shown in their actual form to your audience. It may also be used for enlarging clippings, maps, photographs and other items so they can be traced proportionally correct and in complete detail. The projector permits you to project an illustration or other material out of a book without damaging the publication, The “opaque” uses a 1,000-watt projection lamp and is equipped with a 4 1/2-inch diameter, 22-inch focal length lens. The projector comes with an opaque object-holding device and a conveyor belt loading mechanism that permits uninterrupted projection. It also has an optical pointer that permits details anywhere on the screen to be pointed out by a projected light spot. The roll feed assembly provides a means for handling opaque objects of any length up to 10 inches wide. The thickness of the object should not exceed 1/32 of an inch. To operate the roll feed assembly, stand behind the projector and hold the crank knob in your right hand. Hold the copy in the left hand, faceup, bottom edge toward the screen and feed it into the left side of the projector. When the material is inserted approximately 1 1/2 inches, turn the crank clockwise. The pressure created by the impelled air holds the opaque object flat on the feed belt. When the crank is turned, the opaque object is carried into position. When the next opaque object is to be inserted, repeat the operation. The insertion of one opaque object automatically removes the previous one. Figure 6-5.-The opaque projector. 6-21