Wildlife shooting can be challenging in the best of circumstances. Initially, I located and captured images of some Mexican Free-tailed bats (Tadarida brasiliensis), while they roosted. This was exciting and I enjoyed the experience with the little creatures of the night. So I decided to “up the challenge” a bit, by selecting a moving subject, in the dark, flying at various speeds and directions, and is about 3 inches in size (not including the wingspan), to provide for a challenge of a much greater magnitude.
Most nocturnal creatures have developed skill sets and adaptations which aid them in their nightly forays. Bats are no exception to this rule. The bats I was able to work with were plentiful and also predictable in where they would be hanging out (roosting) for the day, and their willingness to accept strange new contraptions in and around their roosting site eliminated some of the guess work for locating the actual spot for equipment setup. As a point-of-fact, they seemed to be totally unconcerned about the equipment structure for triggering the cameras which also worked to my advantage.
My first concern was what camera equipment I would select for the best depth of field (DOF), and resolution for these captures. I have two full-framed bodies and one cropped frame. I chose my Nikon D810 as the large number of pixels would allow for additional cropping of the final image. Since I would be shooting with the shorter length lens (105mm), it would be necessary to crop subjects from the target area of about 4 foot horizontal measurement.
The next item to address was that of triggering the camera at the precise time for the capture. A remote shutter release could work for tripping the camera from a distance, but the size and speed of the subject made this choice problematic. So I switched to a combination of laser and infrared emitters and receivers. Both were mounted to a 1" PVC frame secured to a set of seamless backdrop poles providing the ability to adjust the height of the frame. See fig 1.
The configuration for the lasers/ir sensor was such as to create a series of three bars of light. See fig 1. When interrupted by the flying mammals, The lights would trigger the shutter release. Note: The above array was modified and the IR emitter eliminated due to the fact that precise location for focus was not as easily establish compared to the lasers and the IR unit I had did not have a receiver end so subjects beyond the frame would also trigger the unit – a large issue when more than 1,000 bats are flying around the camera setup. Once the equipment was modified to only lasers and Cognisys Stopshot controller, there were two bars of light for the triggering. See fig 1
With camera and triggering secured, I had to consider the issue of lighting. Being in the dark, attempting to adjust the ISO, F-stops, and shutter speeds via the camera was out of the question, let alone focusing in the dark. So I utilized small electronic flash heads for illumination, placing them two in front, and one behind the laser trigger beams. These were three Yongnuo 560 IV units. All were set in manual mode. They were dialed down to 1/16th to 1/32nd power so the flash duration would be faster than 1/10,000th sec. One flash was cabled to the flash sync on the shutter while the other two units slaved from the main device. See fig 2
The laser triggers were then coupled to a control box located on the home made bracket attached to the tripod. See fig below.
Once wired to the control box, the triggering setup information was channeled to the high speed shutter trigger attached to the front of the 105mm Micro lens on the D810 body. See fig below.
The high speed shutter was essential in capturing each bat as they passed through the beam. The high speed shutter eliminates the shutter lag commonly experienced when shooting with the focal plane shutter in the standard DSLR camera.
Well, with all of that done, you would think that I would be all set to go. Well, not quite. As in many of my previous posts on shooting wildlife, it is not just the gear and equipment settings that “bring home the bacon”. It is the outdoor observation time prior to the shutter being depressed that makes the difference. And this case was no exception. I decided to pay a scouting visit to the site prior to the shooting to observe the emergent bat flight patterns, and heck, they were great fun to watch anyway, which is why I spend the amount of time I do with wildlife in the first place.
Questions requiring answering:
When do the bats emerge? What patterns can I find in their emergence that would be beneficial for captures? And most important, how can I set up as to cause the lease disturbance to the roosting colony? These were all answered with evening scouting visits to the site. Every animal and/or group of animals will have essential elements of behavior. Do your homework by observing the subjects first. It will save in eliminating frustrating moments later down the road and reduce the stress to the wildlife in the process.
Here are some results. As you can see, I added some with additional post processing to foster some creative ideas for your own captures. You can use them for holiday cards, informational lectures, or just showing them to your friends. Bats should be appreciated here in the USA because they consume a tremendous amount of insects, many of them detrimental to food supplies we raise.