Recently, I posted that my biggest frustration is improper focus.  If you use a point-and-shoot, the solution it pretty simple. You hold down the shutter button halfway until focus is achieved and then push it the rest of the way down. The only reason you’d be likely to end up with poor focus is, as I said before, you’re shooting in an improper mode. For example, you’re shooting a landscape in macro mode.

For us DSLR users, focus becomes another monster all together.

{Factor 1 – Selecting Focus Mode}

The first thing to consider is the mode you’ve set for your camera. In the menu, there will be an area for ‘AF Modes’. The three you may see are:

1.} One-Shot – Suitable for still subjects. Press the shutter halfway and the camera will focus only once. If the subject moves or you want to recompose the shot, you must release the shutter and press it halfway again to refocus.

2.} AI Servo – Also known as ‘continuous focus’ on a Nikon, AI Servo is used to keep a continuous focus on moving subjects until the shutter is pressed all the way. The ‘AI’ stands for ‘artificial intelligence’ and the camera uses these algorithms to predict where a subject is about to be. This is the setting to be used in sports photography and I use it with children on the go. Wikipedia’s entry on AI Servo says it so well: “Before servo focus the photographer would generally pre-focus on an area where he/she thought the best action would take place; today he/she can follow the entire sequence of events, and select the best later.” In AI Servo mode, the camera won’t beep once focus is achieved. It just keeps focusing until you decide to take the picture.

3.} Al Focus – AI Focus mode starts with normal one-shot focusing (hold the shutter down half way and it will beep when focused) but if the subject starts moving, it will switch to AI Servo mode. Certainly, this is clever of the camera, but Nikon doesn’t even have this option. Why? Your subject is either a living, breathing, moving being or it isn’t. I’m either in One-Shot or AI Servo. AI Focus just seems kind of dumb to this Canon user

{Factor 2 – Selecting the AF Area}

In my camera (A Canon 7D) there are three AF Areas and it should be pretty much the same in most cameras.

1.} Single Point AF – this selects one spot to be used for focus. In the viewfinder, you’ll see the little square and you press the shutter halfway and the camera will beep to let you know that focus has been achieved. This mode is useful if you often follow the rule of thirds because you can focus on your subject, slowly re-compose the shot and take the photo. Your subject will be in focus.

2.} Zone AF – Focus points are organized into five different groupings, and the camera uses one of the points in the group to autofocus. Can be used in the thirds composition as above but offers a bigger area for focus, useful for tighter shots and portraits.

3.} Auto Select 19-point AF – All 19 available autofocus points are used. If multiple areas are in focus, all of these points will light up in the viewfinder. This is the mode used in full auto and creative auto modes. Pressing the shutter halfway will display the AF point(s) which have achieved focus. If multiple points are displayed, it means they all have achieved focus. This mode tends to focus the nearest subject. Great for moving subjects.