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.
Good Drawing. Good drawing is as essential in a group as in a single portrait. We have found that the pyramidal arrangement is very simple to handle and will produce the best drawing with the least effort. Too great an emphasis cannot be laid upon the excellent opportunity, afforded in groups, for individual posing of a number of subjects, each one in sympathy with the other members, and each in an easy and natural position. If, after having arranged the group, some of the subjects seem to be awkwardly placed and do not assume an easy position, change them from the standing to a sitting position, or vice versa, and you will generally find one position that will be the more natural.
Lighting. When dealing with a large group, all the available light in the room should be used, for the light necessarily weakens at any considerable distance from the window, and while the end of the group nearest the source of the light will be strongly illuminated the furthest end will be insufficiently so. A flat light should be avoided, but, otherwise, there is plenty of latitude for securing a reasonable amount of light on the face. This gives a new factor to be considered when arranging figures to their best advantage, for taking two end figures which are oppositely lighted, there are many intermediate positions between them that would give intermediate forms of light which will be found to suit a certain figure better than others. This is but one of the many points to be thought of when arranging a group, and the result must always be more or less a compromise.
446. Unless you have a high window and one that is quite wide, you will have difficulty in securing proper light on a large group, such as this. However, for small groups of from two to four members, the ordinary window will answer, and where the light from two windows can be employed, you will experience less difficulty in obtaining the required illumination.
447. To receive the full benefit of all the light coming from your window, place your subject a trifle back from the end of the window, and partly facing the light. You will thereby illuminate the members on the far or shadow end of the group as evenly as those near to the light. With very large groups, however, it is best, as stated before, to arrange your group out-of-doors in the shade of some building, unless you can use a room with an extra large window.
448. Never place a group in the shade of a tree, unless the foliage behind the group is very dense, for if the sun strikes through the foliage it will cause light blotches and spots, which are very displeasing. A wide porch or veranda may be used to good advantage.
Exposure. Group pictures will require more exposure than the single portrait, for there is a larger space with more shadows to cover, and therefore you can calculate on at least double the exposure given single figures.