Selecting the Correct AF Point for Sharper Focus

Has this ever happened to you?  You go off with the family for a nice day at the park.  It’s a great day, beautiful weather and everyone’s having a good time. The kids are playing on the swings and climbing the monkey bars and you top it all off with a nice little picnic lunch. All this while you’re snapping photos left and right, hoping to get some great family shots of the day.  When you finally get home, you download your photos onto your PC only to find out that a lot of your great family shots are not even in focus?  What’s with that?

Trust me, 90’% of the time it’s not the cameras fault, it’s because the camera has locked focus on the wrong focus point. By learning to set your correct focal point and focus mode, you can avoid that from happening to you in the future. 

The problem is these days’ modern cameras can really make life too easy for you. What I mean is that the camera will set the focus point, exposure and white balance all automatically for you, almost guaranteeing a great shot every time, just by pushing the shutter button. Notice I said almost.  By learning how to change and control focus points and focus modes, you can learn how to take better control of your shots and get better photos. 

Cameras these days are actually little high-tech computers and all of them are capable of taking really awesome photos, assuming the user knows what they’re doing. That’s kind of mean, but seriously, kind of true also. I’ll bet your own camera can do plenty of things you aren’t even aware of. By learning to control little things like focus modes and setting focus points, you can concentrate on taking better images consistently.

For myself, when I’m out 

Focus Point - Joystick

shooting I want to make sure that what I want to be in focus, is always in focus when I push the shutter button. Personally, I set up my camera to use the center focal point 99% of the time. I just position my center point on whatever I want to be in focus, recompose, and fire off my shot. Pretty simple right?  You probably already know how to change your focal point and if you don’t, check out your owner’s manual.  It’s usually pretty simple and you should know how to do this quickly on the fly. I’m a Canon shooter and the mode names might be different for various brands, but they are basically the same three:  One Shot AF, Al Servo AF or Al Focus AF.
  

One Shot AF is the mode I use 90% of the time. This mode is best for still subjects. When you press the shutter halfway the camera will focus once. Usually you’ll get a beep and a confirmation light in your viewfinder. While holding it down halfway the focus is locked, you can then recompose or reframe the subject and fire off a shot. If you want to focus on something else, release the button and lock it on something else. Most good DSLR’s also have a AF-ON button which will also lock focus. 

Al Servo AF is best used for moving subjects or where the focusing distance keeps changing. For example, when someone is running towards you and you want them to remain in focus. While holding the shutter button down halfway on your subject, the subject will be focused continuously. Keep in mind, most cameras will not beep even when focus is achieved and the focus confirmation light does not show up. This is also different for various brands, check your manual. 

Al Focus AF in theory is a good idea, but it’s been very hit or miss for me. It has got better over the years, but isn’t reliable enough for my liking. It's been my experience that AI Focus isn't as intelligent as Canon would like you to think.  What it’s supposed to do is to lock focus on my subject and if it starts moving, track my subject. Unfortunately, sometimes it will keep searching for a subject and in the meantime you could miss the shot? The way I figure it, if I need AI Servo, then I'll use AI Servo, otherwise, I'll use One Shot focus mode right?

For myself I usually stay in One-Shot AF unless I know I want to track subjects like at a sporting event or something, and then I’ll switch to Al-Servo AF.  My suggestion would be to train yourself in using your center focal point and see how your images improve.

For those of you that would like to know more, or get another explanation of these modes, check out Neil van Niekerks blog.  Neil is an awesome teacher and a great photographer and share's his knowledge on his Tangents Website. He wrote an article on Focusing Modes that I think you might enjoy. I hope this helps you out in your next shoot. As always, remember, keep shooting and have some fun!