Wednesday, June 20, 2007

Choosing the Right Lens f-Stop for Your Digital Camera

The aperture setting is known as the f-stop. The lowest number f-stop lets the most amount of light reach the image sensor. The next f-stop lets half as much light reach the sensor and so on. You control depth of field with f-stops. When you choose a low f-stop such as f/2.8, more light reaches the image sensor and the depth of field is limited; objects behind your subject and in the foreground are blurry. A low f-stop is ideal for portraits. Notice how your attention is drawn to the model while the background is a colorful blur. When you choose a high f-stop number such as f/16, less light reaches the image sensor and more of your image is in focus, which is desirable when you're shooting a landscape, as shown in the following illustration. Notice how the entire image is sharp, from the tiny blades of grass in the sand to the art deco hotel in the distance.

A high f-stop increases the depth of field.

Capture Images Using Shutter Priority Mode

  1. Turn the camera mode dial to the shutter priority icon. Many cameras use the abbreviation Tv for shutter priority mode.
  2. Choose the desired shutter speed. Refer to your camera manual for the control that sets the shutter speed.
  3. Compose and shoot the picture.
http://tech.yahoo.com/gd/choosing-the-right-lens-f-stop-for-your-digital-camera/191715;_ylt=AkLXbz1JmJ1w8E9kKH1xzrAvLZA5