f-stopAn f-stop is the ratio between the focal length of a lens and the diameter of the aperture. Smaller numbers refer to a larger opening which lets in more light. So an f/2.8 setting would have a larger opening and allow in more light than an f/22 setting. Smaller f-stop numbers, therefore bigger openings, will result in a smaller depth of field for the image. This is often used to draw attention to the subject. Most lenses display an f-stop number on the lens. This is the widest that particular lens will open. Some zoom lenses show a range - eg: f/4.5-f/5.6. This is the maximum opening on the short and long end of the zoom repspectively. |
