Facing page 336.
Having chosen the size of the camera, it is necessary to decide whether plates, flat films, pack films, or roll films are to be employed. For the mountaineer, plates are out of the question; they are too heavy, too easily damaged and too slow to bring into use. Owing, however, to the standard of excellence attained in the manufacture of various types of films, there can nowadays be no advantage in preferring plates, even if weight were not a consideration. Also, in the matter of expense, there is little difference between the cost of plates and that of films. As far as the climber is concerned, flat films (“cut films”) suffer from the same defect as plates, in that they take too much time to use. Pack films are free from this disadvantage, but the packages in which they are contained will not stand rough usage; they are somewhat readily damaged, with the result that light may be admitted. The roll-film is the negative material par excellence for the mountaineer. In a suitably designed camera, the best makes lie perfectly flat. Their bulk and weight are less than those of any other type of negative. Easily packed in air- and waterproof packages which can be sealed with adhesive plaster, they are practically unbreakable and will withstand extraordinarily rough handling. They are quickly changed in broad daylight, free from halation effects, and twelve exposures can be developed together, with little more trouble than attends the developing of a single plate or flat-film negative. These are but a few of the great advantages of roll films from the mountaineer’s point of view. Hence the ideal camera for the climber is a quarter-plate size, roll-film, folding model.
In choosing such a camera, attention should be paid to the following points. The camera should be light, yet strong. It should be as simple as possible and provided only with such mechanism as is essential to the taking of good photographs. All superfluous accessories should be dispensed with. The essential features of a camera are these:—
The back must fit light-tight on to the body. The film-winding mechanism contained in the body should be such that the film is held flat and not scratched on winding. The bellows should be strong and light-tight and should be periodically examined for pin-holes when the camera is in use. Pin-holes, when they occur, are easily repaired by sticking over them a piece of adhesive plaster which can then be blackened with ink or charcoal. The side-struts should lock the base-board firmly when the camera is opened. The front-grip should slide smoothly in the runners and yet fit well, so that when the camera is opened the front standard is held rigid. The shutter is an item of great importance; its timing should be calibrated, and its mechanism be of such a design that the opening and closing movements are as rapid as possible, thus enabling the passing of the maximum amount of light during the time of exposure. The two most important speeds of the shutter are the ¹⁄₅₀ of a second and a high speed such as ¹⁄₂₅₀ or ¹⁄₃₀₀ of a second. It is difficult to hold a camera sufficiently steady to ensure accurate definition with a lesser speed than ¹⁄₅₀ of a second, and this, in the vast majority of cases, will be the standard shutter speed employed. Occasionally, when photographing a rapidly-moving object, such as an avalanche, or a climber jumping a crevasse, the fastest available shutter speed should be used. Integral with the shutter mechanism is the stop, preferably an iris diaphragm. The quantity of light allowed to fall upon the negative should be controlled as far as possible by means of the stop alone, the shutter speed being kept always at ¹⁄₅₀ of a second save in exceptional circumstances. The lens is one of the chief keys to successful photography. From personal experience of many different makes of lenses, I can unhesitatingly recommend the following: Kodak Anastigmats f: 6.3 and f: 4.5, Goerz Dagor or Dogmar f: 4.5 and Zeiss Tessar f: 4.5. These four give excellent definition, and the last is particularly suitable for taking photographs for map-making purposes. For a quarter-plate camera, the focal length should, as a rule, be 4 to 5 inches, rather nearer the former than the latter. The lens, when fitted and the camera opened, must be truly centred with the axis at right angles to the plane of the negative. The view-finder should include no more and no less of the object to be photographed than is actually projected by the lens on to the negative. The focussing scale must be accurately graduated for the lens with which the camera is fitted, and should be provided with an automatic infinity stop which is free from backlash. Both focussing scale and infinity stop, but particularly the latter, must be set with the greatest possible accuracy. This will nearly always be the case in a camera of reputable make secured from the makers themselves. A short cable release is an advantage; it enables one to hold the camera more steady when an exposure is being made. It goes without saying that the camera should be of the best material and workmanship throughout. One of the best makes of cameras procurable and suitable for the mountaineer is the Folding Pocket Kodak Number 3.
The Aiguille du Géant.
Clearing mists.
