Home Movies (1943)

PAGE 238 HOME MOVIES FOR AUCUST "Qoefrg, American" CRAFTSMEN o4e doituj, tlted/i Abate rhe production line of "GOERZ AMERICAN" is formed by skilled men, who through painstaking work create high-grade photo-lenses and optical units for military instruments used by our armed forces on Land — on the Sea — in the Air — These precise optical units are of the greatest importance to our armed forces, for without accurate military instruments for sighting, fire control and photographic aerial reconnaissance their fighting machinery would be of little value to them. aptical science together with our craftsmen, doing their duty on the job in the production line, will hasten victory. aur production is keyed to fill the requirements of our Government. Within limitations we may still be able to supply "GOERZ AMERICAN" lenses of certain types and sizes for civilian use. We suggest your inquiries. Add rets Dept. HM-S information please C. P. GOERZ AMERICAN OPTICAL CO. Office and Factory 317 East 34th Street New York 16, N. Y. JJ rr Qoesig, American PRECISION OPTICS J 6*nce, fS99 Background Projection (Ernest Earhart, Duluth, Minn.) Q: J have read and have been told many conflicting things about the possibility of the amateur filming a motion picture projected upon a translucent screen. What is the real lowdown on this? A: The amateur's desire to accomplish satisfactory background projection photography stems from the increasing use of this medium in production of professional films. Whenever the professional develops a new angle, the amateur is quick to attempt it with an 8mm. or 1 6mm. camera. In the studios, background projection is feasible because the shutters of both the camera and the projection machine c?n be synchronizzed so they will open and close simultaneously. If they did not, there would be an ever changing density of the projected background in the photographed results, caused by the variation of intervals of exposure between projector and camera — the problem that has made background projection almost an impossibility for the amateur. However, recent amateur experiments have demonstrated that reasonably good background projections can be photographed if the projection machine is speeded up and the film projected faster than 16 f.p.s., the speed of the camera. This means that the shutter on the projector will open and close two or more times to one for the camera. While there is some changing in density, it is not so pronounced as when attempting to photograph the background projected at normal speed of 16 f.p.s. It has been further demonstrated that where the background has been specially filmed at 32 f.p.s. and projected at the same speed, the results, when photographed at 16 f.p.s., are reasonably successful. Cinematic Trick (Roy Livingston, Akron, Ohio.) Q: Recently, I saw a picture in a theatre in which the actor played a dual role. There's nothing new in this, of course, except that in several scenes, the actor crossed in front of his twin. I fail to understand how this could be accomplished by the usual method of filming dual role scenes in split stage. Perhaps you can explain. A: Inasmuch as you failed to give title of the picture, we cannot state exactly how the effect you saw was produced. However, since the advent and • Readers: This department is for your benefit. Send in your problems and our technical board will answer your question in these columns. If an answer by mail is desired, enclose addressed stamped envelope. development of background projection, many such dual role shots are photographed by that means. Instead of employing the split stage technique, the scene is filmed with the actor enacting one part. A print of this is projected on the background screen, and the actor, in the dual role, performs again in front of the background projection screen. In the finished film, the action appears to have been filmed simultaneously. Home Reversal (Bryan Chenowith, Cincinnati, O.) Q: In reversing film, can underexposure be corrected by extending the first development? A: Sometimes. But best results are obtained by correctly exposing film in first place and giving it normal development. Lens Speed (Myron Holtzbaugh, Allen town, Pa.) Q: If I convert a regular 1 inch lens tiiken from a 16mm. camera for use with my imm. camera, will speed of the lens be changed? The lens is an f /}.$. A: No, unless the lens is extended by means of shims or extension tubes. Otherwise it retains the same f / value as when used on the 16mm. camera. Titling Feat (T. A. Watson, Kansas City, Mo.) Q: I have endeavored to shoot a title with a moving, natural background by placing the title letters on a panel of glass and setting the glass before the scenic background, filming title and background simultaneously. However, when title letters are in sharp focus, background is out of focus and vice versa. Is there anything I can do to correct this? A: Your problem is depth of focus. It is not always possible to get near objects and distant objects in sharp focus at the same time. On the basis that the smaller the lens stop used, the greater the depth of focus, it follows that you can obtain something like desired results by shooting your title at the smallest stop on your lens — probably f/16. • Continued on Page 264