NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.
Issue link: http://mag.outdoornebraska.gov/i/708333
W ay back in high school, we often asked our calculus teacher why we needed to learn the mindless drivel he was feeding us. He assured us we would use it. "Whatever," we said. Even if I would've believed him at the time, I never would have guessed I'd use that mumbo jumbo to set up a camera trap to photograph bats in flight. Photographers have been using camera traps of some sort to capture wildlife on film since George Shiras pioneered the technology in the early 1900s. The pre-packaged trail cameras used by hunters and more advanced systems used by professionals have come a long way from his tripwires and magnesium flash powder. When I started working on a story on bats, I set the bar high, hoping to use a camera trap to photograph a bat drinking from a water hole. Before I could set my trap, however, I knew I had some numbers to crunch. You can't simply focus on the spot where the beam crosses the water. You have to take into account the lag time between when the bat trips the "wire" and when the camera actually fires. That's .043 seconds. So how much air does a bat cover in that time? That depended on how fast they fly, which depended on the species, and whether or not they slowed down to drink. I settled on the low end at 20 feet per second, and figured a bat would cover 10 inches before I got my first photo. My handy smartphone app told me my depth of field would be about 2 feet at f/16 with my 80-200 zoom pulled back to 80 mm. So I figured I'd get two photos in the 1/10 th of second the bat would be in focus, which meant my flashes could indeed keep up. Whew! Are you still with me? So off I went to a wide spot in a spring fed creek in the bottom of Bull Canyon, a fabulous piece of real estate in western Nebraska, where I was told I would find plenty of bats. I donned waders, set two cameras in the middle of the creek, strobes around it, and the infrared trigger across it. I hung my hat on a plastic post I stuck in the creek bottom, set my focus and exposure and headed across the road to camp. Steaks a friend and I had brought weren't even done cooking when the flashes started popping. The next morning, I stuck the memory cards in the computer and found the setup worked perfectly, except for the one thing. Of the 64 bats I captured in flight that first night, only five were flying the right direction, leaving me with a pile of photos of blurry bat butts. I moved the cameras to the other end of the pond, but gremlins ruled the shoot the next two nights, at some point jumping in front of the trigger and causing the cameras to fire until the memory cards were full. I caught them and reset in the rain the third night, but the little devils came back afer I crawled back in the tent and again left me with a thousand blank frames. Despite going batty from the technical difficulties, I captured about 20 usable frames of 13 different bats. None were drinking and in focus, but they'll do just fine. And I'm sure Mr. Ayres will be happy hear this: You were right. Eric Fowler June 24, 2016 Going Batty 82 NEBRASKAland • AUGUST-SEPTEMBER 2016