Document aJLZ6L6ovgZzg8v8XpeLYdB5N

Fig 10-11 -- An overhead pro jector permits the speaker to face his audience, as he can see his visual without having to turn his back on them Pencil or pointer m speaker's hand shows as shadow "pointer" on projected image behind him He can cover portion of trans parency with ordinary paper if he wants to use `1-2-3" revela tion technique Courtesy 3M Business Products Co filmstrips and 2 by 2 slides by copying with a 35mm camera Filmstrips require even more careful plan ning than slides because it is impossible to rearrange the frames or to add new material to suit specific situations or changing times Also, unless a single-frame camera is used, filmstrip material, unlike the material for slides, must be reduced to standard size reflection copy For a single copy or a few copies, an ordinary 35mm camera and a copy ing stand can be used to photograph art work or color prints Quantity production of film strips is best done by a commercial laboratory If no record script is to be provided with a filmstrip, captions can be inserted over the pictures or m separate frames Generally, however, the speaker gives a commentary that follows the sequence of the strip His timing can vary to suit the detail or impor tance of the individual picture, since each picture can be held to the length of the spoken message Filmstrip projectors for continuous show ing or for showing on rear projection units are also available Overhead projectors In an overhead projector a powerful light shines through a transparency, which is a transparent plastic sheet placed on a glass projection table, to a mirror over the table and then past the speaker to a screen behind him Hand lettering and art work can be done directly on the transparencies either before or during the presentation However, unless special transparent color is applied, the mark ing will show up as black Also, typing, hand lettering, or drawings can be done directly 237