The international photographer (Jan-Dec 1934)

Twenty-six Th, INTERNATIONAL PHOTOGRAPHER October, 1934 A FEW WORDS ABOUT SUN SHADES AND FILTERS (Continued from Page 19) gelatine type filters. I still stick to my guns, or rather statements, for a little reflection will show how true it is that the Canada balsam with which these filters are cemented easily becomes soft and "gooey" in heat. It is likewise easily understandable that the thin gelatine from which filters are made easily wTrinkles, cracks, crumbles, and what-not. Even the colors are not stable, some of them fading or changing color gradually ! However, I have no quarrel with gelatine filters. I again only state my preference — take it or leave it. The solid glass filter, of which type more and more are being made and used right along, is a most practical affair. The good, ones — for which you may have to pay quite a bit — are of excellent optical glass in which the color is inherent. The two surfaces are plane-parallel finished and ground true, hence the minimum of resistance is offered light-rays as they pass through them. The use of filters, or at least the use of a variety of filters, is in my humble opinion greatly over-estimated. I own over a dozen different kinds, yet actually I find use for not more than three for a wide variety of activities. The beginner is likely to sell himself on the idea that a whole battery of filters is necessary before good work can be produced. I believe in simplicity of equipment, for it is remarkable what can be done with limited equipment if it is used properly. A great many gadgets which are on the market today may be desirable, but not necessarily vital. Remember, it is not the equipment you own, it's how you use it that counts. The most useful filter for all general purposes is, of course, a pale or medium density yellow filter. It produces excellent results on either orthochromatic or panchromatic film, and brings in cloud effects as good as anyone could desire. It is the first filter the beginner should consider. As a substitute, a new pale-green filter, known as the panortho (Goerz) has during the past few years become popular. As far as its characteristics go, it approximates the yellow filter. Another type which has made a big hit is the U. V., or ultra-violet protection filter. This one is almost clear glass, but if you look real close you can detect the slightest trace of a greenish hue in it. It is much like the esculin filter. It differs from the yellow filter in that it retards only ultra-violet light. The yellow, as you know, holds back not only ultra-violet, but blue as well. The U. V. is very good for clouds on both orthochromatic or panchromatic film, and a real feature of it is that it does not require prolongation of exposure. This may sound rather off-balance, but let us investigate the matter. There are various makes of U. V. filters. Some require an increase in exposure, while others do not. The Rhaco U. V. filter, for example, is made, not with pigment dye as are most filters, but with a certain chemical compound which must be very accurately made. And because the color is is due to a chemical and not a dye, the light is not retarded to any appreciable degree. Of course it is wrong to say that a filter requires no increase in exposure when used — even a plain piece of glass placed before the camera lens will absorb a certain amount of light — but because the retardation factor is so slight that it would be unnoticed, it can be said, within the limits of truth, that it requires no increase in exposure. Thus the U. V. filter can be placed before the lens without a thought of increasing the exposure. Of course these filters so far mentioned will not produce the effects many amateurs desire, hence additional filters must be brought — into the picture. There seems to be a mania among miniature camera devotees to produce "night effects," almost black skies, etc. For this — if you are interested — a light red filter like the A or F is required. I don't as a general thing, go in for black skies, but once in a while I like a somewhat darker sky than the yellow series gives me. In such cases I like the 23-A, which is even lighter than the A, but still gives pronounced cloud effects and darkens the sky appreciably. If more exaggerated effects are wanted, special filters such as Scheibe offers should be used. He will make up the most amazing combinations on order — if he hasn't what you want in stock. From here on I must leave you to your own devices, for the more common and popular filters are all I really have occasion to use — and I prefer to adhere to them. As a final word, the filter, like the lens, should be carefully protected and kept spotlessly clean. My filters for the Leica are unmounted 32 mm. discs, which are used in the H. C. E. combination sunshade and filter holder. Each one is wrapped in lens-tissue and stacked in a small tin can. These same filters fit the Rhaco combination for the Leica, too. I find it an ideal way of keeping and using filters. You may prefer yours mounted in metal slip-on mounts. For cleaning and THE LARGEST STOCK OF MITCHELL CAMERAS AND CAMERA EQUIPMENT FOR RENTALS IF YOU NEED IT WE HAVE IT CAMERA SUPPLY CO. Cable Address "CAMERAS" RUDDY CERAUS MANAGER 1515 Cahuenga Blvd. Hollywood, Calif. Nite Phone GLadstone 6583 GLadstone 2404 ED ESTABROOK STUDIO RENTALS Please mention The International Photographer when corresponding with advertisers.