Even with modern autofocus systems in DSLR cameras or compact cameras, blur is one of the most common causes of ruined shots. But recognizing the causes will help you to prevent it happening again. There are two main causes for blurred pictures – camera shake and focusing. The effect looks similar, but the causes and solutions are quite different. Here’s what you need…….
Camera Shake
The Cause : As the name implies, camera shake is due to the camera moving during the exposure. It is most common when using either long shutter speeds or longer focal length lenses. During long exposures it’s easy for the camera to move while you take the shot, no matter how steady you think you can hold it, while the greater magnification of long focal length lenses also magnifies any movement, causing camera shake.
The Effect : Blur caused by camera shake affects the whole image, so one way of recognizing this problem is that no area of your shot is sharp. To be sure that camera shake is the problem you need to look closely at a blurred area of your shot. As it is caused by the camera moving during the exposure you should see two or more images of the subject, each slightly shifted from the others. The other telltale sign of camera shake are “lines” connecting blurred areas of the image.
The Cure : The simplest way to cure camera shake is to use a faster shutter speed of at least 1/focal length of the lens, ie if you are using a 200mm lens you’ll need at least 1/200sec (or ideally 1/250sec). When this isn’t possible, or you want to use a long shutter speed for creative effect, use a tripod or beanbag and remote release or self-timer. Incorrect Focusing
The Cause : This occurs in both auto and manual focus modes, due to not focusing precisely. With autofocus it’s possible the focus point used isn’t exactly on the main subject. If you’re using single-shot autofocus or manual it’s also possible that either the camera or the subject moved between the camera focusing and the image being taken. This is more apparent when using long focal length lenses or wide apertures, and the closer you are to the subject, due to the shallower depth-of-field. The Effect : The most obvious result is when an area in front of or behind the subject is sharp, but the main subject is blurred. The subject moving during the exposure causes this too, so check for lines or multiple images. Focusing blur results in even softness across the out-of-focus areas of the pic.
The Cure : You must ensure you focus precisely, especially if you are shooting with a shallow depth-of-field. With autofocus make sure the focusing point is precisely over the part of the subject you want sharp, and if using focus lock or manual focus ensure the distance between the subject and camera doesn’t change.