A careful balance of light
Christian makes a note of the lighting he needs to create the look he wants for each shot, and admits it can sometimes be a lengthy process, even when coaxing a bat into position with food. However, once the bat is in place, he can quickly adjust each of the five Canon Speedlite 430EX III-RT flashes with the Canon Speedlite Transmitter ST-E3-RT. Crucially, using a transmitter means he's not moving around and disturbing the bat. He adjusts the power settings in 1/3 steps for each flash individually via the built-in RF transmitter locked in position on the camera's hotshoe.
"I start with the flash from the top," explains Christian. "Once that looks good, I adjust the two flashes from the front. One is about a metre above and one about a metre below the subject at 45-degree angles, lighting the wings from below and the bat's face from above. The remaining two flashes are positioned behind, both below the bats, to give a sharp edge and separate the bats from the background."
The scientists use a flight cage – a large space enclosed by netting – to prevent the bat flying away. The bat's welfare is paramount. "It's important on a scientific level, as well as morally, that the resulting photographs are authentic," Christian says.
If the photographs need to include an insect, the team will find one that's already dead. But if Christian is photographing a pollinating bat, he must first find the right flower for the shot, which can take time. "In one case, to take photos of nectar-eating bats, I needed the bat-pollinated flower of the liana woody vine. But it took around a week to find suitable mature flowers in the forest," he says.