Photo Technique: Backlighting

A few months ago I started playing about with the placement of the flash unit, and almost immediately hit on a new favorite trick.  When lit from behind, insects look even more zingy than usual. Their translucent bodies glow, they are ringed with little halos, and they stand out dramatically against the background. Below the fold are some samples:

Backlighting involves two major elements. The first is a relatively high-intensity light shining directly on the subject from the opposite direction of the camera. This light gives translucent insects their glow and provides the halo that rings the subject. An easy way to apply the backlight is with an off-camera flash. I normally use Canon's MT-24EX Twin Flash, a nifty device whose two detachable heads allow me to hand-hold one behind the subject. Any flash on a cord will do, however, and natural sunlight is also effective.

The second element is a dark background. The dramatic effect of backlighting stems from a strong contrast between subject and backdrop, and this can be created by directing a flash to just the subject, causing the background to fade to black with fast shutter speeds. Sunlit shots need to be composed with a careful eye towards the background. The shot below works because the backdrop, a shaded palm trunk, is darker than the sun-splashed leafcutter ants:

Combinations of frontlighting and backlighting give an interesting effect. In the image of Acacia ants below, the front of the thorn is lit by a single low-power flash head mounted on the camera. The other head is given full power and is free-held above and slightly behind the subject:

Motionless subjects don't require the high light levels provided by sunlight or flash, and when the camera is stabilized on a tripod any light source can be used. These honeypot ants in a captive colony were shot using a 10-second exposure lit with a florescent bulb:

Feel free to share your own backlit images in the comments below.