American cinematographer (Jan-Dec 1941)

Joe Walker (Continued from Page 160) the industry's best zoom lens design was developed and patented by Walker. Lenses of this design are used for zoom shots on production and on special-effects work in a number of the major studios today. He also designed a 16mm. semizoom lens. Another very practical invention is a method of variable diffusion, by means of which it is possible to alter the degree of diffusion during a scene. This is especially valuable in those dollyshots which begin as a long-shot, for which relatively little diffusion is required, and move in to a close-up which may require much heavier diffusion. Diffusion, to Walker, is another detail which should be studied with scientific care. "All of us know," he says, "that each scene, and each type of picture and player will have its own individual requirements as to diffusion. But there are other points that are all too often overlooked. Diffusion isn't an independent entity: it must be balanced with a lot of other things. The same diffusion disc or filter won't necessarily give you identical results when used over different lenses. For example, a diffuser that will give you a certain effect with a lens that is characteristically brilliant will give an entirely different effect if you use it — even on the same shot — with another lens which inclines toward softness, or toward depressed gradation. "In the same way, diffusion must be coordinated with the film you use, and the processing that film gets. When we changed from the early high-contrast EVERYTHING PHOTOGRAPHIC AND CINEMATIC FOR PROFESSIONAL AND AMATEUR The World's Largest Variety of Cameras and Projectors. Studii Laboratory Equipment with Latest Improvements as Used ii Hollywood Studios. New and Used. BARGAINS. Hollywood Camera Exchange 1600 CAHUENGA BOULEVARD HO 3651 Hollywood, California Cable: Hocamex \JM > and i the L i LANDERS CAMERA RENTALS MOTION PICTURE CAMERAS BLIMPS DOLLIES AND ALL ACCESSORIES PHONE KI-8333 NEW ADDRESS 6373 DELONGPRE AVE. NEAR IVAR STREET HOLLYWOOD Nicht HE-1311 panchromatic to the improved Type IB and then on through Super-Sensitive anl Super-X to today's Plus-X, we've har t make compensating changes in ou1 fusion technique. Maybe we didn"t realize to what extent we did thi each time most of us have juggled ai with our lighting, etc., too: but if look back to the diffusion you were u.-'r. just a few years ago, and compartwith what you consider normal todajl you'll agree. "Diffusion must even take into sideration the particular charade of the film-processing laboratory, too. 1 have sometimes made pictures on othel lots, where the film went through a da ferent laboratory. In every case, I fountf it necessary to experiment a bit before! hand, so I could coordinate diffusion wit j the processing of my negative. "And diffusion discs, like lenses, ha\| their individual characteristics. That i why, if you look into my accessory-casyou will see such a variety of diffusersoften several discs apparently of :h same type. But I know that each has ir individual effects; one, for instance, ma give me, in combination with a certai. lens, just the quality I want for photo graphing, say, Irene Dunne, while an other gives me the slightly different rt suits I'll want when photographing Rosa lind Russell, or some other player. "You probably won't need such an aj sortment as this all the time — but I'v, found that when you do want a particy: lar type of diffusion or lens-quality, it I. a big asset if you have it handy. Inc dentally, since I've been experimenting with the new coated lenses, I've found ai interesting little trick for keeping lenstijj clean and dust-free. You know, some a these lens-coatings aren't particular! rugged, and with a coating only a ft millionths of an inch thick, you wan: * keep the friction of lens-cleaning to ij minimum! So I now keep all my ler.sei when not in use, wrapped up tightly i; the little cellophane bags the still :■use to slip over their flashbulbs. JuiJ slip the lens in and twist the mouth (ijl the bag tightly, and you have an exce, lent, dustproof lens carrier." Walker is one of the few Director. I Photography who never served an aw prenticeship as Assistant and Seconl Cameraman to any other cinematoJ rapher. In his early days, he was a electrical engineer, and firmly convince he was destined to set the electrical worlT afire. His specialties were what a. then called "wireless" and high-tensio electricity. In the latter capacity he w one day called into consultation by early-day studio, to advise them how make a scene in which an actor wasit in an electrified chair and emit sparkl One look told Walker that the studl electrician's set-up would not give ti; sparks wanted — but would undoubted* electrocute the unfortunate actor jus: ti, same. He quickly rigged up a more piaJ tical arrangement which delivered thl desired spark. with perfect -afcty. :;. watching the cameraman at work thaj day, the first, faint doubt arose in W'a' 198 April, 1941 American Cinematographer