The international photographer (Jan-Dec 1940)

No. 2,203,658 — Lens Shifting and Focusing Mechanism. Alvin E. Schubert, assigner to Eastman Kodak Co. Appln. Mar. 9, 1938. 20 claims. A projector having a lamp house slidahly mounted on a base, and a disc having a series of projection lenses of different focal length mounted on it, the disc being movable toward and away from the film gate. No. 2,203,687 — Apparatus Employing Polarized Light for the Production of Stereoscopic Images. Edwin H. Land and Joseph Mahler, assignors to Polaroid Corp.. Delaware. Appln. May 11, 1938, 11 claims. A device for producing stereoscopic pictures by means of polarized light and having overlying surfaces polarizing light different amounts. No. 2,203,767 — Antihalation Photographic Element. Walter D. Baldsiefen, assigner to Du Pont Film Mfg. Corp. Appln. Jan. 25, 1938. 10 claims. A film having an emulsion on one side and a layer of water soluble vinyl alcohol polymer and an anti-halation dye on the other side. No. 2,203,768 — Antihalation Photographic Element. Walter D. Baldsiefen, assignor to Du Pont Film Mfg. Corp. Appln. Jan. 25, 1938. 10 claims. A film having an emulsion on one side of the support and a water soluble carbohydrate glyeollate and an antihalation dye on the other side. No. 2,203,879 — Sound Film Printer. Lawrence T. Sachtleben. assignor to Radio Corp. of America. Appln. July 31, 1937. 3 claims. Efficient Courteous Service ■ EVERYTHING PHOTOGRAPHIC Professional and Amateur ■ New and Used Equipment Bought, Sold and Rented m ART REEVES Camera Supply Co. 1515 North Cahuenga Boulevard HOLLYWOOD CALIFORNIA Cable Address: "CAMERAS" A projection printer having an illuminating aperture which is imaged on the negative film and which is varied in width for correcting errors in intensity of illumination tending to be produced by vignetting in the system. No. 2,204,074 — Photographic Printing. John Eggert and Gerd Heymer, assignors to General Aniline & Film Corp. Appln. May 11, 1936. In Germany May 11, 1935. 6 claims. A process of producing colored prints on a multi-layer film which comprises printing all partial pictures made from an object on a screen film and printing the partial color pictures from the screen film on the multi-layer film. No. 2,204,864 — Shutter for Motion Picture Projectors. Ernest H. Michaelsen, Mass. Appln. Nov. 26, 1938. 9 claims. A shutter for motion picture projectors, having two members rotating about axes on opposite sides of the film, and acting to cut off light progressively from each side. No. 2,204,917— Film Apparatus. Albert W . Tondreau, assignor to Warner Bros. Pictures, Inc. Appln. Feb. 12, 1938. 7 claims. Q. ANd A. box THE QUESTION 0 The following question was received last month from an International Photographer reader. Arrangements have been made whereby such requests for photographic information will be answered by outstanding authorities in the motion picture industry. International Photographer is published in Hollywood as the official magazine of the artists responsible for motion and still photography and who are members of Local 659, lATSE. Other readers desiring professional information are invited to write to the editors. Sirs: I am wondering if you would be kind enough to describe how a dissolving shutter is built, as I would like to see if one can be built in my 8 mm. movie camera by myself. By a dissolving shutter I refer to the type used for fading in. Also can you describe for me the best way to fashion a clutch so that the spring motor may be disengaged during rewinding of the film? Many thanks for your anticipated compliance with my requests and further thanks for the many pleasant hours your magazine has given me. — Herbert L. Kerr 763 W. LaClede Ave., Youngstown, 0. A film drying apparatus having a horizontal spool head spaced between two vertical wall sections and supporting film in loops, with means to direct film drying fluid through the compartment. No. 2,205,179 — Photographic Filter Magazine. Harold E. Schultz, Niagara Falls, N. Y. Appln. Feb. 23, 1938. 5 claims. A filter magazine having a series of filters mounted on a disc which may be rotated to bring different filters in front of the lens. No. 2,205,540 — Photographic Printing Machine. Charles E. Phillimore, assignor to The Bell & Howell Co. Appln. Nov. 1, 1938. 13 claims. A contact printer for motion picture film in which printing is done on an accurate surface, and the curvature of one of the strips may be varied. No. 2.205,755 — Color Photography. Arpad van Biehler, Germany, assignor to General Aniline & Film Corp., N. Y. Appln. Nov. 22, 1935. In Germany Nov. 23, 1934. 2 claims. A method of printing onto a multi-emulsion color film by exposing one layer to a negative and the other two layers to positives, and then developing and coloring the film. THE ANSWER © Unless you happen to be one of those magicians who can build a model ship inside a bottle I imagine the best thing to do would be to forget about building a dissolving shutter in your 8 mm. camera. The first thing that would whip you, I believe, would be room. The principle upon which a dissolving shutter works is to force one half of a double shutter to gradually gain upon the other half until together they form a solid shutter. Since both halves of the shutters must run at all times it is almost imperative that they both be mounted on the same shaft which means that, in order that they may be individually controlled, there must be a shaft within a shaft. Picture a 180° shutter mounted on a half-inch shaft thru the center of which runs a quarter-inch hole. The other 180° shutter would be mounted on a quarter-inch shaft which would use the inside of the half-inch shaft for a bearing. Actuallv the shutter would not be 180° and 180°. They would be whatever the maximum opening of your present shutter happens to be with the second shutter overlapping as much as easily possible; 180° would be the absolute maximum. Incidentally the shutters should be counter balanced. The next step would be to cut a helical slot in the outside shaft corresponding in 28