Motion Picture News (Mar-Apr 1923)

1716 Motion Picture News Description of the Motion Picture Camera (Continued from page 1714) ated. In the automatic dissolve the pressure of a button on the camera throws a clutch into operation that closes the movable shutter blade gradually in a predetermined number of feet of film. With the hand operated dissolve the shutter may be closed gradually by hand in any length of film desired. Generally neither one of these features is provided by camera manufacturers, one of the few exceptions being the Bell & Howell camera, which has an automatic dissolve incorporated in the camera mechanism. So desirable is this form of dissolve that most professional cameramen have had them installed in their cameras by some mechanic who makes a specialty in cinematographic machinery. It is to be expected that most manufacturers will meet the demand for this device in their later models of cameras. Choosing the Camera One of the hardest problems for the student motion picture photographer is the choice of a camera. The popularity of motion pictures has caused many inventors and promotors to place miniature or toy motion picture outfits on the market. While such cameras and projectors may have a field of their own among amateurs who have no serious intention of coming professional motion picture photographers, they are of little use for any other purpose. The reason for their existence is the decreased cost in the operation, by reason of the very small film which they use. This puts them within the reach of those who could not otherwise afford the expense of private production. In some cases, they may be a boon to a student with professional aspirations whose financial position will not permit the purchase of apparatus using standard film. In general, however, the use of toy or miniature picture apparatus by those for whom the contents of this book are intended, is strongly deprecated. In the first place, cheap cameras using standard film may be purchased for the same price as a good miniature camera. In the second place, there is always a chance that the owner or user of a standard camera may be able to dispose of his production in some commercial way. On the other hand, there is no chance for the operator of the miniature camera to obtain any financial return of the expenditure which he has made. By judicious forethought, the owner of a standard camera may conduct his experiments with very short lengths of film, using only a foot or two at a time. The cost of material need not influence even those whose financial restrictions are most stringent. Buying Cheap Camera for Serious Work It must be understood that the purchase of a cheap camera for serious work is not recommended. By all means, purchase the highest grade of camera that your means will allow. Generally speaking, the price of a camera is in fairly direct proportion to the quality of work which it will produce. A cheap camera produces poor work because the manufacturer cannot afford to put accurate workmanship into it. On the other hand, some of the better makes of the cheaper cameras will produce pictures for certain purposes, which are almost, if not quite, as satisfactory as those made by a much higher priced instrument. It would be ridiculous for a man who expected to use his camera only for taking a few topical events for exhibition in a local theatre to buy an expensive studio outfit with an equipment of lenses, diaphragms, hoods, and dissolves, when a cheaper camera would do perfectly well for his purpose. So many different types and brands of cameras have been placed on the market that it is not possible to give a description of all of them here, but most of the principal types are shown in the illustrations and the reader must depend upon his judgment in selecting the type of instrument best adapted to his requirements. Ease of Threading Important The ease or difficulty with which the film may be threaded through the camera has an important bearing upon its usefulness. As a rule, a camera of a straight line threading, that is, one in which theie are no twists in the film in its passage through the camera, is the simplest and most desirable. On the other hand, the more compact models, in which the retorts are placed side by side, cannot be threaded without a twist in the film. The general rule for threading the camera is as follows : Place the feed retort in position. Pull out as much film as is needed to thread the camera. Pass the film over the feed sprocket and open the gate. Place the film smoothly between the side guides with the emulsion towards the lens. Close the gate carefully and latch, leaving a loop of film between the feed sprocket and the upper portion of the gate large enough so that pulling the film down in the gate for six perforations will not draw the loop taut between the sprocket and the top of the gate, and yet not so large that the loop will strike any portion of the camera mechanism. Then leave another similar loop at the bottom of the gate. Carry the film around the take-up sprocket beneath the rollers through the light trap in the retort to the spool in the take-up sprocket and the take-up spool. Fasten the cover of the take-up magazine Give the handle a turn to see that the film is feeding through properly and close the camera. The film in the feed retort must be wound so that when the retort is in place the film is threaded properly, the emulsion side of the film in the gate toward the lens. In straight line threading the loop is not a true loop but only slackness in the film to provide for a quick downward movement of that portion of the film within the gate when it is dragged down by the claws. In cameras with the magazines side by side a true, or return, loop must be made in the film between the feed sprocket and tht gate and between the gate and the take-up sprocket Types of the double return loop threading are found in the DeBrie, Pathe Portable and Newman & Sinclair cameras. The Prevost, carrying its magazines side by side on top of the camera, is an exception, the feed magazine being directly above the feed sprocket and gate, feeds downward in a straight line and simple loop into the gate. From the bottom of the gate it goes upward and to the right in a long single loop, without a twist, to the take-up sprocket, where it feeds directly into the take-up retort. The return, or true, loop is the same sort of a loop as would be formed by wrapping a piece of film in a spiral direction about a round object, while the simple loop of straight threading is merely a slackness in the film without any other twist or turn. In addition to the simple directions gi\en here there are a number of variations in different cameras which provide rollers for guiding the film in various directions. For example, in the old style Gillon a roller is provided which brings the film in a straight line ft 'om the reed retort, from whence it passes over another roller before passing to the feed sprocket ; the object of the second roller being to engage the film around a greater part of the circumference of the feed sprocket, in which only two teeth would engage the film around a greater arc of the sprocket's circumference. H. F. O'Brien Now with Electrical Products Corp. H. F. O'Brien who was formerly with the Los Angeles branch of the Westinghouse Elec. & Mfg. Co., and later electrical engineer of the Famous Players-Lasky Corporation, is now sales engineer for the Electrical Products Corporation of Los Angeles, Cal. Mr. O'Brien has had exceptional opportunities to study all the various engineering phases of the motion picture industry and is probably one of the best informed men in this industry. J. K. Brady who was foreman under Mr. O'Brien is now electrical engineer of the Famous PlayersLasky Corporation. The Electrical Products Corporation is now entering the motion picture field for the purpose of supplying complete electrical equipment. The accompanying photograph shows views of their 150 K.W. portable sub-station which was built by Mr. O'Brien for the Lasky studios. This is the largest and most complete portable sub-station in the motion picture industry. The tower is of Shelby steel tubing and can be raised and lowered by one man. The manner in which the 2,200 volt wiring was made eliminates anv bending of the 2,200 volt cables.