This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
51. With the subject located at exactly the same point, yet the curtains properly arranged to control the angle of light upon the subject, giving top as well as side-light, and at the same time supplying illumination in a more diffused form around the subject, you will produce a correctly lighted negative. The curtains should be arranged to permit the strongest point of light to fall first upon the forehead, then on the cheek, finally on the lips and chin, then gradually blend off into the drapery.
52. To obtain the correct angle of light the first top shade over the subject should be drawn down more than half-way on the skylight-just enough to cut off the flood of light passing over the head, concentrating it there, thus supplying the angle of light on the subject. The second shade should not be drawn down quite so far, while the third should be still shorter than the second. The first, as said before, supplies the angle of light, the other shades merely assisting in carrying out the angle. The shades on the side-light should be drawn sufficiently to prevent a flood of light from the side, and arranged in the same manner as the skylight. By this means, with the first two shades over and alongside the subject, the rays of light will be controlled. The remaining shades should be drawn only sufficiently to carry out this angle and still fully illuminate the subject. Thus you will have under perfect control practically all of the light entering the room.
53. It is necessary to learn how to control light. To do this, consider light in the form of a substance that you might take in your hands and place wherever you desire. The aim in portraiture should be to reproduce the subject and show the strongest characteristics, as well as a true likeness of the individual. To accomplish this, the photographer must thoroughly understand the effects of light, and also know how to control its source in order to produce any desired result.
54. There is no shadow without light; therefore, you must bear in mind that the stronger or more contrasted the light, the deeper the shadow; the softer the light the softer the shadows. In order to produce beautiful round effects, there must be a proper gradation from the highest lights to the deepest shadows. This applies to all photographic lightings.
55. The opaque curtains enable one to secure this control, but they must be handled judiciously, as it is light that makes the picture. Use all of it at your command, so long as it can be done to advantage.
57. In making a portrait, prominence must be given to the head, and in order to do so it must be emphasized by light, while the rest of the figure should be subordinate. Do not misunderstand this, however. It is not intended that the rest of the picture should be left in darkness, but only that there must be more diffused light used. The head must receive three lights of different values and sizes with one predominating light. The old time photograph, with its clear, bright and plainly cut image, while to some extent still in demand, is not what the artistic photographer is endeavoring to produce.
58. The human face and hands are not white, nor anything at all approaching it, and their color value should be sought for in the picture. When properly photographed they should possess a varied range of monochrome tones, thus giving color value. Do not form the impression that we mean subjects should have black faces and hands, or strong faces protruding from the black ground with nothing else visible. This is exactly what is not wanted; at the same time, a flesh tone should not be as white as linen, but more on the mellow order.
59. Study the color value of the face. Note the depth and strength of the various tints, even if there are many shades of colorings. Note the general color scheme, how it is deeper here than there, with bluish tints and deeper yellows, etc. Notice the lips, nostrils, ears, and lines under the eyes and at the sides of the nose. Possibly even on the forehead you will see many shades of color; the lips being red will photograph darker than other parts of the face that have not the same strength of color value, but they will be lighter than the nostrils. The strength of light on the face will also increase the depth of color, and that is why the lighting should be in harmony with other things and aid to faithfully portray the subject. These shades of value will not show in a strongly lighted face. It is, therefore, essential that the lighting be of the correct strength, and that the plate be accurately exposed and properly developed in order to correctly reproduce the flesh values in the plate and subsequently in the finished print. This is the secret in producing catch-lights, roundness and perfect modeling. The beautiful portraits produced by some of our best workers, some of whose results are really marvelous, are only possible from careful study of the reproduction of color values.
60. In portraiture there is a danger of seeing too much - pictures being too sharp. If you are looking at the subject from a point only a few feet distant, mentally review your impression of him. Does his hair appear as sharp as it was sometimes reproduced in the old style photograph? No; you probably see only a little loose hair projecting from the head, or on the forehead, a soft rounding effect of the head and shoulders, and the rest is all a mass. The general form and outline of the features are noticed, but not with absolute sharpness. You have formed a fairly good impression of his clothes, but all in a general way-an impression, with no detail.
61. When the subject is placed too far away from the skylight, it will be quite difficult to secure roundness and atmosphere, for all the light will be from one source; and no matter how much reflected light is employed to illuminate the shadows - even if a correct angle be obtained-the whole portrait will lack life. It is true that only one source of light must be used, but place the subject so that it will receive full illumination from both top and side-light.