International photographer (Feb-Dec 1929)

July, 1929 The INTERNATIONAL PHOTOGRAPHER Twenty-one <iA U^ew tjferiai Qamera * [Brother Waller J. Van Rossem protests that he is no writer and then takes his typewriter in hand and writes me this effusion about the new air camera our friend, Fred Hoefncr, of the Cinema Machine Shops, has just completed for him and, by the way, the beautiful front cover page for this issue of THE INTERNATIONAL PHOTOGRAPHER was photographed by Brother Van Rossem one nice moonlight night out on the blue Pacific, near Monterey, Calif. Give Sir Walter a camera and a full moon and you may depend upon his artistic soul to produce a masterpiece. The letter follows. — Editor's Note.] »>>< You asked me to write you something about the air camera that Fred Hoeffner built for me. Imagine my embarrassment when I find myself "pen-tied." I'm glad your vocation is writing, not mine. Although the photographic line of endeavor has its drawbacks it still seems to me more desirable. Not being able to create any very highly sensitized word emulsion on this sheet of paper, or better, a word picture of this camera, I will let the enclosed picture on a sensitized paper, I better understand, talk for me. That, coupled with the ffllowing description will seem to explain the camera made necessary by the high price of this kind of equipment. This camera is built for the purpose of oblique pictures only and won't serve for mapping. There is a device on the left side of the camera, not seen in the picture, that operates the shutter seen in front of the lens — permitting the changing of films or plates and the resetting of the focal plane shutter without replacing the protecting slide after each exposure. The camera was originally an Eastman 5x7 speed graphic taking any of the graflex attachments, cut film magazine, plate magazine, plate holders or roll film adapter. The other refinements and adaptations such as finder, trigger for tripping the shutter, pointer that operates with the focusing device so that a scale of focus may be marked plainly on the side of the camera are all clearly seen in the accompanying cut picture. A screw on top locks the lens at any desired focus so that shooting down or up the weight of the lens will not alter the focus. The strap is more for protection than service, although is of a length that the full weight of the camera may be supported by it in a handy position while manipulating the various devices in connection with re-loading, re-setting the shutter, etc. Fred Hoeffner is to be complimented upon his workmanship as this "box" was evolved little by little, flights and pictures being made with the incompleted camera as it progressed to insure its adaptability to the taking of oblique air pictures when finished. Any of the brothers who are interested in this kind of work or camera may inspect it at my place any time. "Show your card." I don't doubt that this letter needs plenty of editing; that's your business. If it tells you anything and serves your purpose in the Magazine, that's fine. If it doesn't take good pictures, that's my business. Fraternally, WALTER J. VAN ROSSEM. constituent may affect the condition of any other. However, much can be learned by such attempted separation of effect though it will be necessary to note points where the interrelation of the components is of great importance. Sulfite The reducer in a developer must usually be protected from oxidation by the air and sulfite is most frequently used in this role. That does not seem to be its only effect since it is a solvent for silver bromide. About seventeen years ago C. E. K. Mees and C. W. Piper published a paper dealing with this action of the sulfite. Their results indicate that the amount of silver bromide that can be dissolved in a solution of sodium sulfite increases more than proportionally with the sulfite concentration. Our tests indicate that in developers this effect may become of appreciable importance with the high sulfite concentration used at times. Such solvent action, so long as it is not too great may well tend to produce fine grain in the images developed. In any casq, however, too great a concentration of sulfite may actually reduce the density developed by a given concentration of reducer. That this is truly a solvent action is indicated by the fact that the amount of silver present in the used developer increased markedly at the same point at which the drop of density occurred. The optimum concentration was found to occur at about 75 g-1. Even a concentration of 100 gms. per liter produced a decrease of density on some film, and in no case did concentrations higher than 75 g-1 appear to be of any material aid in increasing developed density. Borax The alkalinity of a developer determines largely the activity of the developing agent. Developers of low alkalinity, low pH, being in general the softer and less contrasty of present commercial developers. The use of borax under normal conditions produces such soft developers of low alkalinity, the alkalinity varying with the quantity of borax and also with the concentration of the other constituents notably metol, in the developers here reported. For this reason, and also since the borax appears to have no direct action on the silver bromide, the results of borax variations must be considered directly with variations of the reducing agent. Reducers With the low borax concentrations emphasized in the first series of tests, the hydroquinone present in the developer had very little developing action. With metol omitted practically no development was obtained even with the longest developing time used, 16 minutes with agitation. Metol, under the same conditions, but (Concluded on Page 3 5)