After photographing outside in daylight for many decades, I began an indoor project last year— using artificial light to make 8×10 black-and-white closeup negatives of small subjects, such as flowers and weed vases. I will describe some of the considerations associated with photographs of this sort that aren’t usually of concern when subjects are larger and outdoors.
Multiple-head studio strobes containing modeling lights and possibly directed into umbrellas have always seemed attractive to me. However, I wouldn’t use that equipment enough to justify the cost, so I chose more economical quartz halogen lights for this project.
A large light source tends to make soft-edged shadows, while a small one gives shadows sharper edges and may result in a harsh appearance. But what really matters is how big the light appears to be from the viewpoint of the subject. A sufficiently close small light may produce the result expected from a larger light, while a large source far away can approach the harshness of a spotlight.
With this in mind, I made a fixture consisting of a 7×7-inch piece of sheet metal with four lamp sockets attached, held at a 90 ̊ angle to a 1×3-inch board two feet long. In front of the four 75- watt bulbs with built-in reflectors is an old Smith-Victor 12-inch diameter fiberglass cloth diffuser; on the bottom of the board is an aluminum plate threaded for a tripod screw. I intended to place the diffuser close enough to the subject so that it would appear large and therefore produce soft shadows. Unfortunately, the difference in distance from the nearest to the farthest parts of the subject (a 3-inch flower, for example) was great enough to produce noticeably uneven illumination. That same difference in distance rapidly becomes less significant as the light source is moved farther away. Consequently, I frequently used a Photoflex Silverdome (a soft box with 500-watt bulb and a 25×31-inch diffusing cloth on the front) instead of my home-made fixture. This provided a broad light source, even when it wasn’t very near the subject.