Camera Aperture controls the amount of light reaching the image sensor through the camera lens The larger the
aperture, the more light that will enter the camera. Conversely, the smaller the aperture, the less amount light
that will reach the image sensor.
Digital photographs are the result of brightness hitting the image sensor. Too much brightness and the picture
will be washed out. Too little brightness and the picture will be too dark. The shutter determines how much
brightness enters the camera, and there are two settings which are related to the shutter - camera aperture and
camera shutter speed.
The Aperture stop of any camera lens is usually expressed in 'f' numbers -- the higher the 'f' number the
smaller the aperture. Standard lenses are normally rated between f/1.8 and f/16.
Each f-number represents a doubling of the amount light that enters the camera as the preceding f-number. For
instance, an f/8 aperture stop will produce an exposure which is twice as bright as an aperture stop of f/16.
Aperture settings possess two basic effects -- the amount of light which strikes the image sensor, and the
'depth of field'. Depth of field refers to the length of the image which is in focus. Large aperture settings have
a shallow depth of field -- this means that the focus of an image is comparatively short which causes foreground
and background objects to appear out of focus. Small apertures maintain a deep depth of field -- almost all the
objects (foreground and background) will stay in focus.
Aperture stop and shutter speed are directly related to each other in determining the amount of light that
enters a camera. A large aperture stop together with a fast shutter speed will let in the same amount of light as a
small aperture stop together with a slow shutter speed. Determining which combination is superior for a certain
situation requires photographic judgment that comes with experience.
To make it easier, most cameras possess an automatic setting which will do the calculations for you. Many
photographers, nonetheless, wish to control aperture and shutter speed for tasteful effect.
Since a large aperture can be used in conjunction with a fast shutter speed, this is often a good combination
for action shots because the fast shutter speed will 'freeze' the movement with a minimum of blurring. Large
apertures can also be used for low light conditions where there is very slight movement in the scene. A large
aperture with a slow shutter speed would be the ideal combination for this scenario.
Standard consumer orientated cameras or point and shoot as they are sometimes referred to, usually have a fixed
aperture, and it is only the more up market camera models that have adjustable aperture stop settings.
One of the main considerations when choosing a digital camera should be the aperture range. This can be
expressed in a number of ways as far as the camera specifications are concerned. Camera specifications normally
quote maximum aperture, aperture range, maximum wide-angle or maximum telephoto apertures, depending on the
It is more useful to understand the aperture range of a particular camera rather than the maximum apertures. A
greater range gives you more versatility in the kinds of shots you can capture. A good range for all-purpose
photography is from f/1.8 to f/16.
Any given lens will have it's own aperture rating which will depend on the actual type. A Telephoto or Zoom
lenses will typically have a lower aperture range than a wide angle lens because more light is required as the
focal length increases. Consequently, larger apertures are needed to produce f-numbers which are consistent with