Aperture
The aperture is that little hole in the lens that allows light into
the camera to reach the film, slide or sensor.
The Aperture is adjustable, allowing you to vary your depth
of field in a scene, i.e. the amount of the scene that you want
in focus from front (the camera) to back (the farthest limit
in a scene).
Aperture uses
Wide Aperture
. Isolating your subject from the background
. To achieve a fast shutter speed
. Capturing Bokeh (out of focus highlights, depends on the
number of aperture blades and the size and shape of the
aperture.
. Shooting in low light
Mid Aperture
. For optimum image quality
. Good depth of field
Small Aperture
. Front to back sharpness
. Achieving a slow shutter speed
. Shooting in very bright conditions
F/Stop
The lens aperture directly affects how much light reaches
the sensor.
An F/Stop can either half or double the amount of light that
reaches the sensor.
Half Stops - F/2.0, F2.8, F/4.0, F/5.6, F/8.0, F/11.0, F/16.0,
F/22.0
Full Stop - F/2.0, F/4.0/ F/8.0, F/16.0
Examples of where Aperture can be applied -
. Landscape F/11.0 - F/16.0
. Portrait F/2.8 for single subject.
F/5.6-F/8.0 for small to medium groups.
F/11.0 - F/13.0 for larger groups.