The title says it all. Are you a slave to your Auto Focus sensor? If you're like me, you enjoy shooting action images. You know the type. It's the kind of image that requires quick reaction, extensive preparation, good luck, and high tech equipment. While we take the latter fro granted, I routinely find technology problems when out in the field. Usually, I'm wishing for the next version of lens or camera to eliminate this or that problem. It doesn't keep me from shooting, it just becomes a thorn in my side waiting for technology to catch up with my vision. Anyway, the point of this article is about depending on the center AF sensor. While most "pro" or "pro-sumer" level cameras have more than one, most people depend on the center sensor for their action shots. It's very simple putting the subject in the biggest part of the image instead of trying to line your subject up with one of the others. I totally understand the challenges. You're trying to get an inflight image of a quick flying Snow Goose, but you don't want something that looks like everything else. You're actually trying to create a piece of art and that means good composition along with everything else. But you'd just as soon get the image, any image, instead of trying to use any but the center sensor. The problem is, you get so used to using the center sensor, you might forget there are others when shooting less dynamic images. Most of this article will talk about the compositional pros and cons of using the center focus sensor. I'll leave the other stuff--exposure for example--for another article.

Let's examine why you're using the center AF sensor. I found pointing a long lens at a quickly moving target is beyond complicated. It's practically impossible. Add to this, the target isn't flying a smooth, consistent profile. The problem gets bigger. You're wondering, how did all those gunners in WWII shoot down those moving aircraft? They used lots and lots of bullets. People didn't just point, shoot and bring down aircraft. Lots and lots of opportunities were needed to get the aircraft. It's just hard work. The same thing is going on here. You're trying to get the bird in your cross-hairs, focus the image, and fire the trigger. That's a lot of stuff to do.

One thing you'll notice is it's much easier to shoot these things when the subject is small in the view-finder. That's because there's lots of room for the subject to move before having to make a correction. There's lots of error bounds. Now, get the subject a lot closer so it fills the screen. The problem is much harder if you don't want to cut a wing, tail, or nose off. You need quick reactions and great technique to work under these conditions. Shoot, if you don't care about the composition it gets much easier. If you want to make something artistically interesting, you've got a challenge.

There's no question as to why people choose to use the center focus sensor. Life is complicated verses impossible if you're using something else. But, there's a problem. Every image using the same technique looks the same. Composition that are the same make images look the same regardless of the subject. Shoot a duck with the center sensor, it looks like a godwit doing the same. Totally depending on the center focus sensor exclusively it the first major step towards mediocre photography. If you haven't guessed, I've always been a proponent towards avoiding the typcial. Go down a different path. Sure, get inspiration from the other folks but don't copy their work. Create your own vision. Just because technology hasn't advanced enough to let you use something other than the center focus sensor, that's not an excuse. Try harder, waste alot of film--you'll be happier in the end.

Now assuming you use the auto focus features on your camera, what can we do to minimize some of the problems. First, deactivate AF function when you're using the shutter release. If you don't, every time you press the shutter button the camera will try to focus on something. If your subject isn't under the active sensor--it's probably the center one by the way--something else will rip into focus and ruin your image. I think using the shutter button to activate the AF functions leads people to instinctively restrict themselves to the AF sensor. Don't do it. Instead deactivate the shutter button and depend on your other buttons to turn on AF. That way you get to choose when you use your AF instead of the camera.