Since I started posting images of soaring Andean condors and swooping eagles from my recent trip to Patagonia Chile and Argentina, a lot of people have asked me how it was that I got such sharp shots trying to follow a fast bird in flight.
If I had to sum up the answer in a nutshell, I'd say it in two words: animal behavior. Yes, of course, you pump up your ISO and open your aperture wide. How much so will depend in large part on the available ambient light. Then you also put your camera focal setting to follow a moving object (AI Servo in Canon's case) and on high speed continuous shooting. But while those technical adjustments will get you an effective shutter speed (800th of a second or more in my specific case), they don't guarantee a sharp image. Animal behavior is the final necessary ingredient.
Here's an idea about what I mean: This was my first time shooting both the condors, the largest flying birds in the world, and eagles from this location in Chilean Patagonia. I picked up one key piece of information from my guide: the birds are so big that they like to conserve energy by gliding on thermal updrafts so they don't have to flap those large wings so much to stay in the air.
As I observed the birds soaring over my head or down below the high overlook I was on, I realized the birds were repeating a flight pattern to keep surfing the thermals. That knowledge and observation enabled me to start predicting exactly where the birds would fly to next, where they would turn around in the air, where they would swoop and dive and bank. Being able to predict their movement made me a much more effective shooter when it came to getting freeze-frame shots that made every feather stand out tack sharp. The trick, I guess you could say, was to be able to think like a bird.
