I learned a little about photographing birds in flight the other day. I was shooting white birds against snow-covered mountains, a very low contrast scene, and the camera would not autofocus for beans. it would focus and track perfectly along a darker tree line so I knew it was not an equipment problem, but every time they flew into the white background the camera would lose focus and start hunting wildly. I found a solution to the problem but don’t get too excited because it is a compromise and does not works as well if the system were tracking properly.
First let me say that I have mentioned several times before about using the back focus button when using continuous focus for birds in flight. Most if not all DSLR’s have the function. You can set a button on the back of the camera to control autofocus and the shutter release button is used only for actuating the shutter and vibration reduction if you are using it. The more I learn the more I feel it is an essential technique for photographing birds. If you have not tried it before you owe it to yourself to try and to stick with it for a while because it will pay off in the end.
OK- so here is the trick. Normally when shooting Bif’s I have the focus lock set to off. Nikon calls it “Focus tracking with lock on” and Canon “AI Servo tracking sensitivity. Focus lock is a setting you should have buried deep in your menu but when it is turned off the camera will (in tracking mode) refocus as fast as it can, essentially keeping focus as quickly as you can pan the camera. This setting has options, it differs from camera to camera, but it should be something like “short, medium, and long”. These setting tell the camera how long to hold focus before trying to refocus. Here is the trick-Set the focus lock to one of those settings, acquire your subject in a high contrast scene and follow it to the low contrast area. As it enters the low contrast scene your camera will now hold focus for a short period of time. Depending on the distance to your subject, aperture, and focal plane, there is a pretty good chance your bird will still be nice and sharp. It doesn’t always work but it will enough that you just might think that you have made the impossible possible.
Here is a little slide show I made with some of my favorite images from the recent Bosque Del Apache trip.
Thanks for reading and have a happy and safe holiday
You can see more of my images at ronboyddesign.com