The Educational screen (c1922-c1956])

Page 186 The Educational Screen on the Recomar, swing the focusing device into place (sketch 1) and shift the camera lens or change the distance from diagram to lens to get the proper-sized image on the ground glass. Critical focusing is done with the Recomar lens rachet while examining the image with a magnifying glass. The focusing chamber is swung aside but its base is not removed from the plaie holder guides (sketch 2). The diaphragm is usually stopped to 8 and the shutter closed. The Argus film carrier, already loaded with film, is pushed into place against the butt of the focusing unit and the cover of the plate holder attached to the Argus is pulled out sufficiently for proper exposure of the film. All ex- posures are made with the shutter control on the Recomar. After exposure, the cover is pushed back into place and the film turned for the next exposure. The Argus film carrier is pulled out of position far enough to allow the focusing unit to be swung into place for the next picture. This procedure eliminates the delay involved in replacing the film case on the plate holder track after each exposure. Exposures can be taken almost as rapidly as the pictures to be copied are arranged. Eastman Safety Positive or Agfa Positive film may Fks i ^O.A be used for both negative and positive strips and de- veloped in Eastman D-16 or Agfa Positive Film De- veloper. Process film is also excellent for reproduction Sketch 1 Sketch 2 Fa. V- of black and white line drawings. Color pictures are accurately reproduced with Kodachrome A. Film bought in bulk is much cheaper than spool film, costing about one cent per foot. If only a few pictures are to be copied, a short strip of film is rolled onto the spool. This method eliminates the necessity of exposing a complete roll of 18 or 36 frames before development. The shorter strips are cut between frames and made into 2" x 2" slides. We have found the S.V.E. Tri-Purpose Projector to be excellent for both film strips and slides. The combination Recomar and Argus described here has a definite place in the field of visual education and its advantages are: low cost, flexibility, accuracy in focusing; it can be used for closeups or distant views, black and white or color reproduction, copying or landscapes. The authors acknowledge the services of Mr. Leon Bassett in assembling this photographic unit and for his line draw- ings showing the specifications. I Developing a Community Program with Visual Aids {Concluded from page 183) the effectiveness of instruction something that would be lacking without their use. Approved teaching aids should have definite instructional value comparable to that of the teaching aids which have been purchased by boards of education. Teaching aids containing more than a minimum amount of advertising or implications which point to the absolute superiority of the specific product or of a particular commercial organization should not be used in the public schools. With this type of procedure, many of these organizations are able to produce films which have many values for use in the schools and community. Cooperation with the press, radio stations, theatres, departments of City government, and all other agencies utilizes main avenues for action relating to those com- munity interests in which all are vitally concerned. An integrated program by use of visual and auditory aids provides a balanced education for the public schools and the entire community.