A bald eagle and focus challenge.

Long focal lengths are notorious for narrow depths of field. Add to this the need to often shoot wide open and you have a recipe for out-of-focus subjects. If a branch, leaf, another bird, or even the wrong part of the right bird becomes the point of focus you've got a messed up shot. With focus being so critical, it is important to ensure that you've nailed it.

Even when there is nothing between you and your subject there is plenty of opportunity to get it wrong. If the focus point is not quite on the bird the lens may focus on infinity or go into a focusing spasm trying to find something to lock onto. If you do get your subject in focus, is it the right part of it? This is well illustrated when photographing reptiles as their long bodies make it easy to get a sharp middle and a blurry head.

Here are some practical suggestions when focusing to improve the chance of getting the shot you want.

• Chose center point focusing. This makes allows the camera to focus on only the very center of the image and not be led astray by peripheral objects.


• Make the center point of focus as small as possible. By selecting the smallest area of focus you are more likely to define the exact point you want in focus. For most wildlife, I choose the eye.


• Use focus lock and not continuous focus. Small centerpoint focus, lock onto the subject's eye, then reframe to obtain the photograph you want. You have to keep your finger half-way down on the shutter button to maintain the lock. This method works well if your subject is not moving about.


• If your subject is moving about in a controlled fashion or you want to shoot in rapid succession change over to continuous focus and change from center area to variable point focus. This will allow you to keep a point in focus but you can pick exactly where that focus point is. The continuous focus feature allows the focus to change constantly. As long as your finger is half-way down on the shutter button the lens will continue to focus; the variable focus point allows you to put the area of critical focus in the compositional position desired.


• 3D focusing is a feature found on some cameras. It allows the area of focus to change with the position of the subject. It is more effective in cameras equipped with many focus zones using fast-focusing lenses. I use this option when shooting birds in flight as their rapid change in position often means losing focus. When using this focus mode I set my vibration stabilization setting to "active" mode.

For the image above (left) I used center point locking focus. I made sure the eagle's eye was in the center part of the viewfinder and pressed my shutter button half-way down. Once the focus was locked I could reframe the image to get the composition I wanted. Since the eagle was just leisurely sitting overseeing his domain I had lots of time. The above image (right) shows what happens when the wrong thing becomes the point of focus. This is a situation many of us have experienced. Using the right focus parameters will ensure better results.

Thanks for reading.     Ericspix     Eric Svendsen