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.
42. By controlling the light is meant the manipulation of the shades and curtains, also diffusing and reflecting screens, so as to control the volume of light as it falls upon the subject. In making portrait lightings the angle of light must come from the side and front; seldom from behind the subject. Therefore, when making these lightings place the subject at one end of the light; never in the middle of it. With the subject at one side of the light there will be-after arranging curtains and obtaining the angle of light-sufficient illumination surrounding the subject to supply softness and detail. Working in this way the subject is always at one side of the light and your camera at the other. In fact, by this method the center of the skylight will be always between the camera and subject, and sufficient illumination will surround the subject to supply detail in the shadows, while the proper angle of light will be under control.
43. In order to demonstrate, in the simplest manner possible, the controlling of the angle of light, we will apply these methods to the most universally used style of lighting, known as Plain Portrait or Broad Lighting. In illustrating the manner of controlling the light, photographs of the skylight room have been reproduced, showing the curtaining of the skylight. The hip-light has been selected for this purpose for the reason that this style of skylight is almost universally used. However, the same methods may be applied to any light, whether hip, single-slant, or even perpendicular.
44. Plain Portrait Lighting is a style of illumination in which more of the face is in light than in shadow, the light falling on the front of the subject usually at an angle of about 45 degrees. Before demonstrating the control of the light, let us first consider the proper location at which to place the sitter to receive the benefit of both the side and top-light; also the point at which he will receive the benefit of the strongest source of light, and finally, see that the light falls upon him at the proper angle.
45. To demonstrate more clearly the controlling of light, we will consider the effect of this light in a room 18 ft. wide by 36 ft. in length, in which the light is located within 5 ft. of one end of the room. The size of the top-light, 11 ft. high by 10 ft. wide; the top of the side-light, 7 ft. from the floor; the light itself beginning within 3 ft. of the floor, thus giving a side-light 4 x 10 ft. and a top-light 10 x 11 ft. The top-light is built into the room at an angle of about 45 degrees.
46. In placing subjects under this light, when a Plain Portrait or Broad Lighting is the purpose in view, we would place them at one end of the room, about on a line with the end of the side-light and distant from it about 9 ft. (See diagram of skylight and room.) In this way the subject receives the full benefit of all light, and yet we have absolute control over the angle of light as it falls upon the sitter. With the shades properly arranged, we would be able to make a good Plain Portrait Lighting from this point. However, should none of the shades be drawn on the skylight or side-light-in other words, should the light be used wide open, with the subject placed in the same position-a very flat result would be produced, This illustrates the effect of uncontrolled light. The face will not have the least trace of character in it; every angle and shadow will be flattened, and all lines entirely eliminated. Owing to the fact that the light falls on the lines and shadows from all directions, the shadows will be illuminated to the same degree as those parts which should receive the highest points of light. This demonstrates that some control over the angle of light must be had. We must preserve the little shadows and characteristic points of the face; objectionable features must also be overcome by subduing the light on them, all this being accomplished by the manner in which the light falls upon the face.
MISS FLORENCE KAHN (In Ibsen's Play, "When We Dead Awaken.").
Study No. 4 Rudolf Eickemeyer
PORTRAIT STUDY Study No. 5-See Page 576, Vol. VIII Burr McIntosh.
47. To control this light so it will fall at any point and any angle we desire, emphasizing some portions and subduing others, we resort to the use of curtains, by means of which, if properly arranged, absolute control of every ray of light entering the room is obtained.
48. If all of the top shades on a hip-light, or the upper shades of a single-slant light be drawn down, and the subject placed some distance from the side-light, one side of the face will be strongly lighted, while the other side will be a black shadow. The shadow line from the nose will be almost straight across the face, instead of falling at an angle as it should. The top of the head, as said before, will be dark, owing to lack of illumination over it. The strongest point of light, instead of being on the forehead, will appear on the cheek and jaw. This clearly demonstrates that more top-light is required.
49. We cite these extreme cases, as their effects are so marked that we believe they will cause the reader to understand more clearly the advantages and objects of the different manipulations of the curtains with a view to the proper control of the light. As you will readily observe, the pulling down of all the shades of the skylight changes the angle of light, and probably the strongest point of illumination from the side-light will fall about three or four feet from the window. The benefit of all the top-light, which, in fact, should be made use of, is thereby lost.
50. Considering the reverse arrangement of curtains -the side-light entirely cut off and all the light coming from overhead-the shadow from the nose will fall directly over the lips; in other words, the lines will be perpendicular instead of falling at an angle and the eyes will be quite hollow. With the subject placed still farther under the light, the results would be more to the extreme, but from the fact that the subject receives the full benefit of all front light as well as top-light, the eyes will retain more roundness. The lighting, however, will be entirely wrong, as there will be no angle visible. Should it be necessary to work under a top-light, better roundness would be produced by placing the subject farther from the source of light, with the face turned a trifle into the shadow, although working under such conditions is quite difficult.