Digital Photography Terms by: Whitney Hodge

Exposure value refers to the amount of light for a given exposure. It is denoted as a single number. Its value is subsequently used to calculate the correct combination of shutter speed and aperture at a given ISO speed of the sensor.


Depth of field is the range of distance within the subject that is acceptably sharp. The depth of field varies depending on camera type, aperture and focusing distance. The depth of field does not abruptly change from sharp to unsharp, but instead occurs as a gradual transition.

A Diaphragm is a round device on the face of the camera that has an opening at its end known as the “aperture“. The function of the diaphragm is to make sure that light only enters the camera’s lens through the aperture. While the aperture can be widened or narrowed to allow more or less light into the camera, the diaphragm is meant to shut out all other extraneous light so that the film isn’t overexposed.

ISO range of a camera refers to how sensitive the camera is to light. For instance, a low ISO number (100 or under) is not very sensitive to light, and is best for shots in good lighting conditions. A higher ISO range means that the camera will be suitable for photography in darker conditions.

Aperture: When your lens is open very wide, the background is typically out of focus. Wide-open aperture is good for portrait photographs, when you don't want the background to interfere with your subject. When your lens is only open a small amount, everything from the foreground to the background is in focus. This aperture is used for landscape photographs, so that all of the scenery in the photo is in focus.

Shutter Speed: If you want to capture still photos of fast motion (like pressing pause on your VCR or DVD) you have to use a fast shutter speed. Many sports use very fast shutter speeds to capture the peak moment and freeze it in time. If the subject of your photo is not moving, or you want to show the passage of time (with a running river or waterfall), then you can use a slower shutter speed.

White Balance: Natural sunlight is a different color from the light produced by tungsten and fluorescent light bulbs. While our eyes adjust naturally to these changes, cameras do not. If your camera has a white balance setting, it will adjust automatically to different colored lights, and produce natural color no matter what the light source is. You can also adjust the white balance manually.