The international photographer (Jan-Dec 1934)

July, 1V34 T h INTERNATIONAL PHOTOC R A I' HER Fifteen the difference might he so slight as to he negligible, still it exists, and must, therefore, he reckoned with. Your shutter — how accurate is it? When you set it for 1 /100th second, does it give exactly that exposure on the film? Here again, this is a very small matter, still it should he added to the discrepancies of the film speed. For the sake of argument let us suppose the lens is exactly f :4.5 when you set the diaphragm at f :4.5. We now attempt to calculate a proper exposure. We have numerous considerations to think of. Even in daylight the color may vary from day to day ; the intensity certainly does vary and the objects photographed present all sorts of conditions which make a correct estimate well-nigh impossible. The exposure meter comes to the rescue, but even this most useful instrument must be set properly as to film speed before it is capable of giving a proper light-interpretation. So we have just a few of the many conditions confronting us each time we take the camera in hand. Naturally enough these are of trifling importance for all practical purposes, for the latitude of the modern photographic emulsion will more than "cover up" small errors. But those workers who dig right down into the depths of photography find these things out and then the fun begins, as it were. When it comes to development of the negative, we again contact various problems. For example, each worker has his pet formula which he swears by. Strangely enough, few photographers agree as to the choice of developer. This may be accounted for by the fact that each individual has different conditions to contend with and, likewise, has his own ideas regarding what constitutes a "good" negative. Some like a heavy or meaty negative ; others prefer a thin one. Obviously no one formula can produce a negative to the liking of all. To be strictly correct, we must realize that a different formula should be used for each grade, type and make of emulsion. Yet ordinarily any and all films are developed in one formula. The technical boys like to talk about gamma, and can show you curves and figures which make the hair of the uninitiated fairly stand on end. It is true that gamma is important, but it will vary with the worker. To be correct, we should say that gamma should be controlled and applied to each type of picture, for some subjects are at their best when developed at a low gamma, others at a high gamma. The miniature camera has made us all "grain conscious." The old-fashioned formulas are no longer in use, for today a formula must have fine grain characteristics to be fashionable. This is well, for grain is a most decidedly annoying factor. However, in the opinion of many, we seem to have swung too far over in our efforts towards fine grain. In other words, there are now in use formulas which give a marvelously fine grain, but sacrifice richness and detail. This should not be. If we can secure fineness of grain sufficient for our purpose, why sacrifice important qualities in the negative? So reason some keen amateurs who have not been misled about fine grain. In Europe they secure fine grain results by using the various special fine grain films. In America we work a bit differently. We insist on speed in our films, hence we are forced to use comparatively grainy films and try to cover up by using fine grain formulas. But what're the odds? Photography is a grand game regardless of whether you are working for technical data, pictorial and art results, or just casual snapshots. If you use a movie camera, miniature camera, or a box camera — aren't we all more or less brothers under the skin? The technical fans supply us with our modern emulsions and formulas, to say nothing of making it possible for us to know the focal length and speed of our lenses without the necessity of sitting down and getting all balled up in a maze of figures. The arty workers give us pictures that delight our eyes — in short, each one contributes something to the game. We all share and share alike. A grand game. THE lens that brings great ideas to life Special effects which baffle photographic technique— and are therefore shelved as "impractical" — are brought to life with the B & H Cooke Varo lens. Because of its almost miraculous ability to "zoom", it accomplishes subtleties and ingenious dramatic transitions not hitherto possible. At F 3.5 the range is from 40 mm. to 50 mm. ; at F 4.5 from 40 mm. to 85 mm., and at F 5.6 and F 8 the full "zoom", from 40 mm. to 120 mm., is obtainable. Adjustable stops provide for limiting the "zoom" as desired. One crank controls all moving parts. The iris is varied automatically with the focal length to keep the f/ value BELL & HOWELL COMPANY constant. Close focusing is done with auxiliary lenses. Write for full details. Sometimes available on rental to responsible studios. The B & H Cooke Speed Panchro Lenses B & H Cooke F 2 Speed Panchro Lenses are corrected for the blue and red rather than blue and yellow rays. They give the most critical definition under the most difficult of modern lighting conditions. Made in eleven focal lengths, from 24 to 108 mm. B & H Cooke F 2.5 Panchro Lenses, at considerably lower prices, meet many needs where their speed is adequate. Seven focal lengths from 32 to 162 mm. Write for details and prices. 1849 Larchmont Ave., Chicago; 11 West 42nd St., New York ; 716 North La Brea Ave., Hollywood ; 320 Regent St., London (B & H Co., Ltd.) Established 1907. Please mention The International Photographer when corresponding with advertisers.