2. Aperture
In photography, Aperture is a device that controls the amount of light admitted through an
opening. Aperture is the unit of measurement that defines the size of the opening in the lens
that can be adjusted to control the amount of light reaching the film/digital sensor. The size of
the aperture is measured in F-stop.
3. Shutter Speed
The shutter speed is the unit of measurement which determines how long the shutter
remains open as the picture is taken. (The slower the shutter speed, the longer the
exposure time.) The shutter speed combined with the aperture control the total amount
of light reaching the sensor. Shutter speeds are measured in seconds or fractions of a
second.
For example 2, 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000,
1/4000, 1/8000. Each speed increment halves the amount of light.
4. ISO
ISO is a common short name for the International
Organisation for Standardization. The ISO on a digital SLR
camera refers to film speed. Although most cameras are
now most likely not film at all, but rather digital, the ISO
camera setting still has the same function as older film
cameras. ISO determines how sensitive the image sensor is
to light.
• The lower the ISO number, the slower the speed.
• The higher the ISO number the faster the speed.
