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.
Single Slant Skylight. In Illustration No. 1, Fig. 2, we present a single slant light 12 ft. wide and 14 ft. high, the light beginning 3 ft. from the floor and slanting into* the room at an angle from 13° to 35°. This size of light is suitable for a room 25 to 30 ft. wide, and from 30 to 40 ft. long. In a room of this width work may be performed all around the sitter, and at the same time, at sufficient distance from the light to secure brilliancy and roundness. This light, under such conditions, will be much easier to work, as there will be less trouble with reflections; and also because only one set of curtains will be needed for controlling the light. This size and style of light will answer every purpose for bust portraits, figures or groups, in a room of this size. The light should be located, if possible, 10 ft. from one end of the room. This will give ample room for working from either end of the light for all classes of work, except, perhaps, very large groups, which will need to be made from the farther end of the room.
Curtaining The Light. In curtaining a hip-light you should have two sets of opaque shades (a deep green color is the best), fitted to spring rollers. One set should be attached to the top of the skylight, extending down to the side-light. The second set should be attached to the bottom of the side-light, extending to the lower edge of the top-light. These shades should be at least a foot longer than the length required to cover the given space. They should also overlap each other at least 4 inches on either side. The ordinary window-blind stock of good quality is in common use, and can be obtained in almost any width, 36-inch shades being generally employed. In fact it is better to have a greater number of shades of this width than wider shades and less of them, because with a 36-inch shade better control of a smaller space of light can be had than with those of larger size.
Muslin Diffusing Curtains. In addition to the opaque shades attached to spring rollers, you should have a set of muslin curtains running crosswise of the skylight. These should be made of light-weight white muslin, with rings attached to the hem at both ends, by which they may be strung on wires, stretched from one side of the light to the other. These diffusing curtains will not always be required, so when not in use they should be slipped to one end of the light. The principal use of the diffusing curtains is to overcome bad reflections. They are practically indispensable if the sun shines on the light. Instruction in the manipulation of the diffusing curtains is given for each style of lighting in their respective chapters.
29. With a single-slant light there is practically no need for diffusing curtains, unless the light faces other than in a northern direction. If it does it will be necessary to diffuse the strong sunlight. With a north light, however, there will be sufficient diffusion, as work can be done further from the source of light. A single-slant light will require two sets of opaque shades on spring rollers, one running from the top of the light past the center, and another set running from the bottom of the light to above the center. With these shades and a diffusing screen on a movable standard, absolute control of all the light in the room can be acquired.