Blurred Background

When we want to emphasize a particular object in a photograph, we often use the blurred background technique. In doing this, the photographer intentionally obscures the background of an image in order to accentuate an object in the foreground. This type of photography is commonly used in shots of nature scenes, as well as portraits.

Importance. This photographic concept is useful for elimminating any distractions that could potentially be in the picture. For instance, if the photographer wanted to shoot a picture of a flower without the hindrance of numerous trees in the background, he would purposefully blur the background of the image in order to emphasize the flower and nothing else in the frame. Utilizing this technique forces the viewer to focus on what the photographer had originally intended as the subject of the shot.

Method. In order to place the emphasis on solely the subject of an image, the photography must utilize his lens to throw the background out of focus. The depth of field (amount of in-focus distance, see next post) in the picture needs to be reduced enough so that the intended subject is sharp and the background is blurred. To shorten the depth of field, it is necessary to use a wide aperture (the size of the opening in the camera that allows light to enter). If a severe blur is desired, the photographer will need to use a low f-stop as well (see Figure 1). Additionally, the focus length (or width of the picture angle achieved through the use of an optical zoom) will need to be increased and the distance between the subject and the camera will need to be decreased. This way, there will be less background, therefore leaving less room for distraction in the photograph.