Definitions and Terms

Aperture

The aperture is the "hole" through which light enters the camera to expose the film or digital sensor. The diameter of the aperture is controlled by the f-stop setting, and the amount of time it remains open is controlled by the shutter speed setting.

Aperture Priority

The "aperture priority" setting will determine the shutter speed for a proper exposure, given your choice of f-stop.

Bracketing

Bracketing is the practice of taking multiple pictures of the same scene with varying exposures to maximize the odds of getting the perfect exposure. Typically, one will take three shots, one at the expected proper exposure, one slightly overexposed, and another slightly underexposed.

Depth of Field

Depth of Field is the region of the scene that appears in focus.

A "shallow" depth of field means that a very narrow range of distances from the lens will appear in focus, while objects closer or farther away will appear out of focus. Shallow depth of field is very effective in portriat photography or any other situation where you do not want the background to distract the viewer's attention from the intended subject.

Conversely, a "deep" depth of field is effective for landscape photography where that sprig of grass or wildflower one foot from the lens is in focus, all the way to the mountain range background out at infinity.

Shallow Depth of Field

f-stop

The f/stop setting controls the diameter of the aperture. The larger the f/stop number, the smaller the aperture will be during exposure.

ISO Speed

Shutter Priority

The "shutter priority" setting will determine the f-stop for a proper exposure, given your choice of shutter speed.

Shutter Speed

Shutter Speed is the amount of time the shutter allows light to enter through the aperture, exposing the film or digital sensor.

Shutter speeds are measured in seconds or fractions of seconds. Faster speeds are better for scenes with motion that you would like to capture with a high degree of sharpness. Slower speeds are good for intentionally blurring motion or capturing static scenes in low-light conditions.