The overhead projector and its uses

The Overhead Projector In the 70s the Ministry of Education embarked on a large scale to uplift the quality of teaching by providing training of teachers and providing audio visual hardware and software to all schools and colleges. The Institute of Education organized a series of Educational Technological Courses for Audio Visual Aids co-ordinators whom in turn to train all teachers in their schools on the development and usage of these audio and visual hardware and software Educational Audio Visual Suppliers sprang up overnight and sales persons descended on the schools with their samples to convince the co-ordinators of the effectiveness of their teaching aids. The Ministry of Education supplied a slew of standard audio visual equipment to all schools in order to encourage teachers to use them for better classroom teaching. Some of the equipment were the Overhead projectors, the 35mm filmstrip projectors, the slide projectors, the opaque projectors, the 16 mm film projectors, the video and audio cassette recorders and players. Among the list of equipment, the most popular equipment was the Overhead Projector. Its uses not only restricted to the use of projecting images or printing from transparencies. It was also used for enlarging pictures on screens for artists to trace the outlines of the pictures they had. To view 35 mm slides, one need not held them against a light source. He placed them on the Fresnel lens and switch on the projector. One could easily pick up the slides he wanted. During a play, if one wanted to have darker shadows or to brighten up a character, the OHPs were used. To show the shapes of different objects such as leaves, or animals, just placed the samples or cut-outs on the lighted lens and focused them on the screen. One could also use different shapes of objects on the lens to represent different characters in his story that he was telling. The transparencies The most often used of the transparencies was to stand behind a projector and write on a blank one. One could focus on the audience and at the same time write the main points on the transparencies. One could also have prepared transparencies. One could reveal the blocked out prepared points one by one while he was engaging with the audience. The transparencies could be prepared either by writing with transparency markers or machine printed using the 3M transparency maker. Later photo-copier could also be used to make transparencies. Colour transparencies could also be made using the more expensive blanks. There were correction pens as well as correction erasers that came with the markers. Roll transparencies were also available should one wish to save time and to prevent any transparency slip up. Should one wish to make animated movements, a motorized roller was also available. With the introduction of digitalized images on cameras, visualizers and computers, these information are transmitted to the digitalized projectors which are conveniently and permanently fixed on the ceiling, and beam on the screen. The overhead projectors became redundant overnight.