Ring lights produce illumination that's essentially axial--which makes the light very flat and suitable for subjects that don’t respond well to more directional lighting.
Axial Lighting is light that follows the same line as the lens axis. Ring lights and similar gear like my Nikon SB29S, with its dual flashtubes are very handy for close-up photography in the field. But for an occasional shot from a copy stand, you don’t absolutely need a ring light to get axial lighting for close-up work. Here’s how you can achieve this kind of lighting for very little cost.
A clever angle
Support a thin, optically flat and thoroughly clean sheet of glass below the camera lens as shown in the diagram. A 5x7 to 8x10 sheet from a picture frame will do nicely for many smaller subjects. You can cut supporting triangles from wood and cement them to the glass, or use metal shelf brackets.
Point a small flash horizontally at the glass. Angle the glass at 45° to the light and to the vertical lens axis. Place the object to be photographed below the glass and camera lens.
The light from the flash is reflected from the glass to the object and illuminates it. You photograph the subject through the glass. To prevent stray light from the opposite side of the glass from being reflected into the lens and spoiling the image, place a dark shield on the side of the glass opposite to the flash. A simple piece of black cardboard will do. Even better, enclose all but the camera side and flash side of the setup with a cardboard box. The box should be painted black on the inside.
This setup also works well with tungsten lights.
You can determine exposure with a flash meter, by testing or, better yet, by using a TTL flash with an cord. As a starting point, figure you’ll lose at least one to two stops of light by using this set-up.
Try point-source lighting for detail
Axial lighting isn’t a cure-all for all close-up work. Sometimes such flat lighting will prevent you from revealing surface details that add drama or vital information to your photos. This is where we get to “sharp” lighting. In such cases a more “point-source” type of lighting is called for. For our purposes point-source means that the light source is significantly smaller than the size of the subject being photographed. If you place a regular shoe-mount flash within a few inches of your little subject, the effect of the flash becomes much like a bank light.
Building your own point-source light is easy and only costs a pittance. The key items are a TTL flash and a six-inch length of 1/4-inch clear acrylic rod. The rod will act as a fiber-optic light pipe and effectively reduce the light size to a quarter-inch in diameter. Flatten both ends of the rod and sand them with 400-grit emery paper. N cut three rectangular pieces of photo mount board or similar material to fit over the front of your flash. Glue these boards into a three-layer sandwich. They will block the front of your flash and serve to support the acrylic rod.
Punch or drill a 1/4-inch hole through the center of the board sandwich. Push the rod through this hole so one end is flush with the innermost board. Secure the rod with epoxy or hot-melt glue. Attach the assembly to your flash with black gaffer’s or electrical tape as shown here and your close-up light is ready to use.
Connect the flash to your camera with a TTL sync cord and you are ready to get some dramatic lighting. The light will spread out from the acrylic rod (as it does with all but sharply focused spotlights), but still provides a nice, contrasty lighting effect. To soften the shadows a bit, place a white reflecting card opposite the flash like you would when using any other light source.
The disadvantage? You will lose a lot of light with this attachment. While I used ISO 100 film to shoot these samples, in many cases it’s best to use faster film (or a higher ISO setting on a digital camera) to gain more depth of field.
If your flash has a repeating “strobe” function, you can use it to preview the lighting and as an aid in aiming the light.
Commercial devices that offer improvements on this basic do-it-yourself idea are available. One is the Novoflex Coldlight Microlight Plus. It has three flexible fiber optic pipes to make it easier to position your light where you want it. A built-in cold light source can be used as a modeling light or for taking pictures. In addition, you can attach your own flash to it if you prefer flash lighting.
Use pipe lighting for transparent subjects
The final trick we’ll cover here is “pipe lighting”. Some transparent subjects like certain mineral crystals and cut glass are difficult to light attractively. One solution is to light them from beneath so the light comes from within the subject. To achieve this, simply place a TTL flash inside a box and aim it upwards through an appropriately sized hole. Place the transparent subject over the hole and your subject will be lit nicely. The quartz crystal shown here was lit by a TTL flash using this type of setup.
To get a feel for what this kind of lighting will do, you may want to experiment using an ordinary tungsten light at first. Actually, I used a Photogenic Minispot for the glassware photo seen here. I set the white balance for “tungsten” on my digital camera to get more normal-looking coloration. The Minispot is a great product, particularly for black-and-white photography. I am still using the original bulb after 30 years!
By the way, please don’t leave an incandescent lamp on for long inside the box! It will smoke.
As you can see, there are a variety of close-up lighting techniques—each tailored to enhance the unique characteristics of diverse subjects. Give them a try the n time you delve into the wild and wonderful world of close-up photography.