Holy camera trap Batman... it worked!

Typically seen as a ghostly shadow, flitting through summer nights at speed, this Brown Long-Eared Bat has been frozen in time by a very high-speed flash, allowing an opportunity to see these remarkable creatures in glorious detail. Brown Long-Eared bats are one of the most common and widely distributed species in the UK, and are typically found in woodlands. With a wingspan of 20–30 cm, it's also one of our largest bats. Just look at those magnificent ears!

The story of how I captured these images is below.

Brown Long-Eared Bat, Cambridge

Fourth attempt caught this beautiful front view of a Brown Long-Eared Bat (1 out of 150 images)

I first realised bats were visiting the wildlife pond I maintain in a nearby woodland after reviewing some trail camera footage. It was the first time I had ever recorded bats with a trail camera — and completely new behaviour for that site. The video immediately set me thinking: could I capture a bat in flight image with my DSLR camera trap kit?

The challenge was how.

Trail camera clips showed that the bats visited most nights but only for a few seconds, no more than ten, looping low over the pond in tight figures-of-eight as they hawked for flying insects. They were fast, unpredictable, and fleeting.

My only previous attempt at photographing bats had been in Costa Rica, where nectar-feeding species visit specific flowers at night. There, it's a question of reaction time as you wait beside your camera setup with flashes primed, pressing the shutter as soon as a bat appears in the faint pool of light from a small torch. But that approach was impossible here: I wasn’t about to spend entire nights in the woods for just a handful of seconds of activity. This project required a camera trap solution, one that could be triggered at exactly the right moment.

Testing Triggers

A little online research and home testing quickly ruled out passive infrared (PIR) sensors: they weren’t responsive or precise enough to catch a flying bat. Fortunately, I also had a Hahnel Captur Module Pro in my kit, which can trigger cameras or flashes via several methods, including an infrared (IR) beam.

Most tutorials I found on high-speed flash photography with this system used the method of leaving the camera shutter open on a long exposure and letting the trigger fire only the flashes when the subject broke the beam. This is extremely responsive as the flash units fire the instant the IR beam is broken, whereas linking the trigger to the camera shutter introduces a short but consistent lag in response time. I confirmed the lag in home tests using a bouncing tennis ball; it was slight, but enough to make photographing a bat at the exact beam-

breaking moment highly unlikely.

A Workable Solution

My workaround relied on probability rather than perfect timing. Since the bats circled the pond surface for a few seconds, I set the Hahnel trigger to fire a short burst of images after each trigger event. Using the Captur’s programmable controls, I configured the camera to shoot continuously for three seconds, at roughly 6 frames per second.

The technical setup was:

• Camera: manual mode, 1/200s at f/16

• ISO: 2000

• Lighting: two Nikon SB-28 speedlites, 1/8 power (fast enough to recycle between frames)

• Triggering: the Hahnel capture module pro system fired the camera shutter via a hahnel receiver and shutter release cable; flashes were triggered wirelessly using Camtraption transmitters/receivers.

• Housing: everything enclosed in DIY weatherproof boxes.

The camera was prefocused on the centre of the bats’ typical flight path, while the IR beam was positioned about 20 cm above the water surface (any lower produced false triggers). After that, success depended entirely on whether a bat chose to fly through the beam.

The Result

On only the third night, I got lucky: one trigger burst produced a sharp image of a bat in flight, wings spread as it skimmed the pond. On my fourth attempt, I caught a bat flying toward the camera, I couldn’t be happier. These are images I wasn’t sure I'd capture in a month of trying, but it's a reminder that with camera traps, patience and a little luck are always part of the process.