PicsArt Monthly November Issue 2013 | Page 18

What is Aperture Controlling Depth of Focus If a camera is an eye, the aperture is its pupil. It is the hole through which light passes and is focused, and it is created and controlled by the iris surrounding it. In a camera's case, the iris (or diaphragm) is made of several small metal blades overlaid in a circular pattern. Just as our pupils widen to let in more light in the dark, we can open our apertures in low light, and close them in brightness. What is less obvious, though, is the effect the aperture's size has on depth of field. What is Depth of Field? @shamzrapz A photo's depth of field is the distance between the furthest and closest objects that are in focus. If both the foreground and the background of a scene are sharp, it has a large depth of field. If a small area is in focus, but the front and back fall off into blur, it has a small or short depth of field. These are also known as deep focus and shallow focus. Smaller Aperture, Sharper Image The depth of field is controlled by the aperture. A large aperture, while it lets in more light, shortens and softens the focal plane (the precise distance at which your lens is focused). This is because the light comes in at steeper angles, causing it to scatter more. As the aperture shrinks, only the straight-on light rays can enter. This cuts down the total light, but sharpens the image and increases the d ?????????????(?????A?????5?????((0