Closeups with Artificial Light

By Howard Bond Back to

Bond_MJ_2007_1

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.

The lights

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.

My remaining lights are a 500-watt reflector spot for backlighting and two 6-inch clamp-on reflectors from the hardware store that contain 75-watt reflector bulbs that have become spot- lights with the addition of taped-on cones of wrapping paper that taper from 6 inches to 2 inches. There are also assorted light stands, white mount-board reflectors, and two kinds of backgrounds.

To show a flower without a visible means of support, I fastened galvanized iron wire to a quart bottle of water with a 6-inch end projecting upward at a 45 ̊ angle. This is bent if necessary to keep it pointed at the camera. The background consists of a black, white, or gray card with a hole in the center, placed over the wire and leaned against the bottle. To prevent wilting, I kept the flower stem in water using a little tube that florists supply, which can be taped to the iron wire.

If a vessel is to be in the picture, I draw a chair up to the far side of the card table and place a piece of 16×20 or 16×24 mount board on the seat, leaning against the table. I tape one end of a piece of background paper (I use Canson Mi-Teintes, which is available in 191⁄2×151⁄2-inch pieces in many colors at our art supply store) to the top of the mount board, so it is nearly vertical, while the other end is taped to the table, making it horizontal. If the soft box is above and slightly behind the subject, the tilt of the mount board can be adjusted to control the amount of light hitting the nearly vertical end of the background paper. In this way, I have obtained up to a two-stop difference between the two ends of the paper, with a gradual transition.

The ranges of film sizes and lens focal lengths that can produce satisfactory resolution in finished prints can’t readily be specified because degree of enlargement and viewing distance vary so much. If negatives are large, they will be enlarged less and, therefore, don’t need to be as sharp. On the other hand, larger negatives need longer lenses, which have two drawbacks. When Dick Dokas and I compared all of our view-camera lenses some years ago, we found that as focal length increased, resolution decreased steadily, regardless of the brand of the lens. Second, the small apertures that longer lenses typically require to obtain adequate depth of field cause losses of resolution because of diffraction, and this gets worse as the aperture gets smaller. In spite of this, Dick and I have found that moderate enlargements (to 11×14 or 16×20) can be adequately sharp when made from 8×10 negatives exposed at ƒ/45 to ƒ/64, a range needed for this project.

Using a lens that is shorter than normal for a given film size can be convenient because it doesn’t require the bellows to
be extended as much as a normal lens would. Also, a lens that ordinarily wouldn’t cover a particular film size may do so if the lens-to-film distance is greatly increased for a closeup. I have made good 11×14 negatives with the image a lot bigger than life-size, using a 150mm lens that doesn’t even cover 5×7 inches when focused on a distant scene.

In the 1990s, while making closeup photographs of bristlecone pine trees, I bought a 210mm Nikkor macro (designed for closeups) view-camera lens, hoping to get more resolution. When focused 1:1, diffraction made its performance at ƒ/45 no better than my old 210mm Fujinon W. During my present project, I used a borrowed 180mm Schneider Macro-Symmar in addition to my 180 mm Apo-Symmar. Again, at the small apertures (ƒ/45– ƒ/64) I needed and distances closer than 1:1, diffraction obscured any advantage the macro lens might have had.

Except for some small camera lenses that focus by changing the spacing of elements rather than by moving the whole lens, the apertures marked on a lens are inaccurate when the lens-to- subject distance is less than about nine times the focal length. A chart from my article, “Exposure Corrections for Closeups” (PT, January/February, 2003), indicates how much to increase exposures to compensate for this. The increase is best done by lowering the meter’s film-speed setting, since the aperture is presumably dictated by depth-of-field needs.

With the effective film speed lowered by a closeup correction, extra exposure is more likely to be needed to correct for reciprocity departure. If the indicated exposure is one second or longer, consult the table in my article, “B&W Reciprocity Departure Revisited” (PT, July/August, 2003, also posted on the Web site). This table is the result of much research and in some cases is significantly different

from old data still being published by the film manufacturer. When strobe lights are not used for flower photographs, movement during long exposures sometimes occurs. I had a case where a leaf was sharp in a 2-second exposure but was blurred when a filter increased the exposure to 21 seconds. This argues in favor of fast film when using hot lights.

Often, something like a flower petal is too small to be measured accurately by a 1 ̊ spot meter. If the meter is brought close enough for the spot to fit the petal, the image in the meter is out of focus, causing the area being measured to spread out and be poorly defined. Our local camera store measured the threads on my meter (30.5 mm for a digital Pentax 1 ̊ spot meter) and ordered a set of Hoya 1-, 2-, and 3-diopter supplementary lenses. With both the 2- and 3-diopter lenses on the Pentax, the meter’s internal image is in focus when close enough to measure a spot 5 mm in diameter.

About the photographs

Rose and Driftwood was lit simply, with the Silverdome soft box above and slightly behind. A piece of white mount board leaned toward the camera just out of the picture across the bottom, to fill in the foreground. The black background paper appears gray where a lot of light hit it.

The background for Hibiscus was a piece of white mount board leaning against the water bottle, with the wire going through a hole in the middle. The 500-watt reflector spot backlit the flower from behind and to the right. A piece of mount board was suspended between this light and the lens to prevent flare. The Silverdome, lighting from the front left, brought out the contours of the flower.

The vase shown in Inlaid Weed Vase was made by Roger Sloan from a block of walnut and cross sections of oak roots. I adjusted the tilt of the mount board supporting the far end of the blue background paper to obtain the maximum (two stop) difference in illumination between the two ends of this paper from the overhead soft box. The weeds stand out because they were closer to the Silverdome and the two improvised spot- lights were hitting them from the sides.

Whereas the preceding subjects were large enough to be done easily with a normal focal-length (300mm) lens, the Gerber Daisy was photographed with a 180mm lens in order to make the image three times life size. Even with the shorter lens, the 8×10 Deardorff bellows was nearly fully extended. The intricate structures surrounding the center of the daisy are satisfactorily sharp in an 11×14 print. It is surprising that diffraction was not a bigger problem, since the four-stop closeup correction means that the effective aperture was four stops smaller than the ƒ/45 I set, i.e, ƒ/180.


About the Author

Howard Bond
HBond
Howard Bond is a fine art photographer who teaches printing, unsharp masking, D/B masking, Zone System, and view camera workshops. His photographs are in the collections of more than 30 museums in the United States and Europe. He has had over 60 one-man and 40 group exhibitions. The recipient of a Michigan Council for the Arts Creative Artist Grant, he has published 2 books and 23 limited edition portfolios of prints. His educational activities include 24 years of writing for Photo Techniques magazine and 34 years of teaching workshops that have been attended by over 2000 photographers from 5 continents.