45. Plates

Plates. Various speeds and kinds of plates will be required for various classes of commercial work, but where an all-around plate is desired, the exact nature of the lighting, conditions for the subject you are to photograph not being known, the more rapid brands should be employed, for with them it is possible to obtain a sufficient amount of exposure, at least, while if a very slow plate were used it might be difficult - or perhaps impossible - to make a negative at all. Where the objects to be photographed remain stationary, the length of the exposure, so far as the moving of the object itself is concerned, does not have to be taken into consideration, and a slow plate should be used, for with it there is greater latitude and the results are invariably clearer and contain more contrast. If a sufficient amount of exposure be given, and the subject has been properly lighted, no difficulty will be experienced in securing the proper amount of detail in the shadows, and by careful development the high-lights will, practically speaking, take care of themselves.

46. The fastest brands of plates are especially suited for all extremely short exposures and flashlight work. Whenever it is necessary to work in changeable and uncertain light, and especially in the winter, when under-exposures are frequent, fast plates should be used.

47. For the copying of drawings, manuscript, plans and printed matter, and in all cases where black and white effects are desired, the slowest plate obtainable should be employed. These plates generally require ten to fifteen times longer exposure than the rapid plates.

48. Slow plates should be employed for the reproduction of the grain of wood in mahogany furniture, dark oak, bird's-eye maple, etc. Slow orthochromatic plates have considerable latitude, but lack, to a certain extent, the strong density in the middle tones, which is important in work belonging to this class. Flower and landscape photography require the use of the special orthochromatic plate, in order that the correct rendering of color values be given. The brilliant coloring of the foliage is much more dull, black and lifeless when the ordinary plate is used. In fact, for general all-around work in which the correct rendering of color is desired, the orthochromatic plate should be employed.

49. The non-halation plates will be found useful for many kinds of subjects, and especially are they valuable in photographing interiors when strong lights or out-of-door openings are included in the view, which always reproduce very dense and with considerable halation at the edges. When photographing shops containing machinery, rooms with furniture, or any highly polished articles, there is always danger of strong reflections, which will cause halation, and for these a non-halation plate may be used to advantage. Very soft detail in the high-lights under most trying conditions can be secured with them. The slight additional cost of non-halation plates over the ordinary plates will be outweighed by their advantages.

50. The non-halation plate does not, however, do away with halation in extreme cases, and there are other methods which may be employed in conjunction with the ordinary plate, whereby halation may be practically eliminated from the most difficult views possible to photograph. (See Illustration No. 52a, Page 142, and Illustration No. 53a, Page 146.) In the chapter on Special Development, Volume II, is given full information as to the manner of producing excellent negatives of subjects photographed under the most difficult and trying light conditions, with the total absence of halation in the final results.