Sharpen Your Focus

How many times has a good shot been ruined by a vital part of the image being out of focus? A lot, I would guess. We often rely too much on auto-focus letting the camera make the decisions. Let’s look at some ways to ensure that the important parts of the image are sharp by taking back control.

Nearly all cameras these days have auto-focus which virtually guarantees at least some of your image will be in focus. Which part, however, might not be the part you want to be sharp. Most auto-focus systems will use an area of the image to focus on – usually a central point. This may be fine for most general scenes, but there will be times when it leads to parts of the image loosing sharpness.

Sometimes, particularly if you have a fairly prominent foreground, your auto-focus will focus on this area and leave the main subject out of focus. Especially if you have a narrow depth of field. This can happen if the Focus Area is set to “closest”. You can choose “single” Focus Area to get around this. Auto-focus can be confused under certain conditions when the focus area contains objects at different distances, unusual contrast or a finely detailed subject. If you find the main subject going out of focus when using auto-focus, try letting the camera focus on something at a similar distance, hold the shutter part way down to hold the focus, and recompose the shot. If all else fails you can always use Manual Focus!

When it comes to focus, depth of field is very important. Depth of field is the range of focus within an image. It is governed by the aperture of the lens. The larger the aperture the narrower the depth of field. Conversely, the smaller the aperture the greater the depth of field. Confusingly, the higher the aperture number the smaller the actual aperture. So, f11 gives a smaller aperture than f4. If you are using Aperture Priority exposure you are in control of the depth of field and can alter it to suit what you want. Otherwise the camera will set the aperture depending on the shutter speed in order to get the correct exposure. It is a good idea to use the preview button to see what the depth of field will look like in the final image.

If you are in auto-focus you can choose between Single-Servo or Continuous-Servo. This is basically to handle moving objects. Generally, single-servro will ensure a sharp, focused image. Continuous-servo may be a better choice for erratically moving objects which are constantly changing distance.

If your camera has manual focusing controls, learn to use them. You will almost certainly come across situations where auto-focus lets you down, and if you know how to use manual focusing you will get more out of your photography. Manual control is almost always needed when photographing close ups, and controlling depth of field. It allows you to make precise adjustments and inevitably control where in your image the sharpness lies.


Lastly, if your camera has an electronic range finder, life is even easier. In Manual Focus mode, make sure your subject is in the focus area, half press the shutter-release, turn the focusing ring until the in-focus indicator is displayed and you are focused. No excuses! Enjoy your photography.