We walked down to the river in the dark, and I stood beside the pool where the river widened after rushing under the bridge, waiting for my night vision to kick in. After a while, the presence of bats made itself felt – flicks of black against light parts of my field of vision, occasionally resolving into movement of small objects for a short distance before disappearing into the darkness again.

Bill set up the torch with its powerful beam crossing the water from the bank on which we stood  to the channel emerging from the sluice gate. We waited for a while, then suddenly a pair of bats appeared out of the blackness above the pool and flashed in and out of the light beam.

I set up my camera and flash gun and waited for them to appear again. After a few minutes, a bat appeared and I took a shot at it. Checked the camera – no bat. However, they continued to appear, usually in pairs, zoming around the pool at a height of one or two feet, looking a bit like fighter planes, leader and wingman. I continued shooting, and eventually starting getting photographs with bats in – sometimes parts of bats at the edge of the photo, but quite a few reasonably central.

The bats kept coming for a long time, although I didn’t notice the time going by as I was enjoying myself so much. This kind of photography appeals to the hunter in me, although by the end, I felt like a hunter who had not brought home much for the family meal. The best of the photographs were mostly out of focus, and those that were in focus suffered from movement blur.

However, I noticed that the bats frequently flew in and out of an opening (see the photograph at the top of the page) leading to a sluice gate, and I had an idea for getting some decent photographs. A flashgun which was triggered when a bat interrupted an infrared beam across the opening would probably be fast enough to produce a photograph in focus.

Stopping the motion blur will involve firing a flashgun at low power, which means that it will need to be closer to the bat.

And the camera’s shutter will need to be open when the bat interrupts the beam.

Hmm …