Exposure

Underexposed photograph.  Taken with a high shutter speed and medium sized aperture

Overexposed photograph. Taken with a low shutter speed and medium sized aperture.

Perfectly exposed photograph. Taken with a medium shutter speed and wide aperture.

F-stop and aperture

Wide aperture, low f-stop.

A wide aperture/ low f-stop

Shutter speed 

In photography, shutter speed or exposure time is the length of time when the film or digital sensor inside the camera is exposed to light, also when a camera’s shutter is open when taking a photograph. The amount of light that reaches the film or image sensor is proportional to the exposure time.

Slow shutter speed ( 2 secs)  fast shutter speed (1/1000th second )

– a fast shutter speed may be used to photograph birds in flight or a fast sport (eg swimming, running etc)

– a slow shutter speed may be used to photograph movement, (eg a dancer or a waterfall)

ISO

ISO measures the sensitivity of the image sensor. The lower the number the less sensitive the camera is to light and the finer the grain. Higher numbers mean the sensor becomes more sensitive to light which allows you to use your camera in darker situations. The cost of doing so is more grain/noise within the final outcome.

Depth of field

Depth of Field: The distance between the nearest and the furthest objects giving a focused image. A narrow depth of field means that its main focus point will be the only thing in focus, leaving everything else in a blur. Where as a Large depth of field means that most things in the frame will be in focus.