I’ve seen many gorgeous images of macro subjects taken with available light. But as with many other subjects, a lot of factors must fall into place to create a successful natural-light photo. The beautiful light has to be where the subject is located, the subject’s appearance has to coincide with the time of the gorgeous light and the setting must be perfect for its direction. Rather than leave these factors to fate, wouldn’t it be nice to have a fallback plan at your disposal to create beautiful macro images even if it’s heavily overcast? The solution is a rather easy one. Use flash. It can be used as a fill light, main light or in tandem with multiple flashes to produce dramatic and pleasing results.
The advantages of flash are many. First off, they provide a large burst of light, so small apertures can be used. You gain a lot of depth of field over shooting with the lens wide open. This is important when you work with macro subjects, as critical focus is measured in millimeters. Even the slightest error in focusing results in an out-of-focus subject or a subject that may have a sharp wing instead of a sharp eye. Secondly, a flash helps offset movement of the tiny critter or flower if the wind is blowing. In that the duration of the flash is fast, the slow-moving insect will look as if it’s standing still. The same goes for the flower that’s moved by the wind. An additional benefit is it frees you up from using a tripod. This is advantageous as you can move more efficiently, and the tripod is just another item that may scare away your subject.
Two Flashes: In the close up of the dahlia, I used a setup with two flashes. Each was mounted to a bracket that mounted to the tripod socket of my camera. I positioned the “main” light on the right side of the bracket and the “fill” light on the left. The fill light was dialed down to one half stop less than that of the main light. Had I not used two flashes, distracting shadows from the overlapping petals of the dahlia would have appeared. The fill light softened the shadows and resulted in a more pleasing effect.
Flash As Fill: In the image of the arched flower stalk, I used flash to fill in the shadow side, which softened the contrast. It’s been said that a good nature shot can’t be made in the middle of the day because the light is too harsh. While this rings true for grand scenics and large animals, it isn’t gospel for macro subjects. The reason has to do with the size of the subject relative to the size of the light. When a small subject is lit with a powerful flash, the photographer takes control of the light. In relation to the scenic or in the case of a large animal, the amount of light that’s emitted from the flash isn’t strong enough to light the subject. The flower photo was made late morning with the sun behind and to its right. I set the amount of fill light to minus one-third stop. This created a pleasing balance between the ambient light and the light from the flash.
Add a Background And Light It: In the photo of the praying mantis, I used two lights. The main light was to the left of the subject and placed inside a 12-inch softbox. The soft light wrapped around the mantis and flower to give the effect of light on a bright overcast day. The habitat was very busy, so I used a cardboard background on which I painted light and dark green blobs. It creates a nice out-of-focus background for macro subjects. I lit the background with a second small flash dialed down one and a third stops. Had I not dialed down the intensity of the light on the background, it would have commanded too much attention.