4. APERTURE
A device that controls the amount of light admitted through an
opening. In photography and digital photography , 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
or digital sensor. The size of the aperture is measured in F-stop
5. SHUTTER SPEED
In photography and digital photography the shutter speed is the unit of
measurement which determines how long shutter remains open as the
picture is taken. The slower the shutter speed, the longer the exposure time.
The shutter speed and aperture together control the total amount of light
reaching the sensor. Shutter speeds are expressed 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.
6. ISO
International Statdred Organization lower the ISO number,
the less sensitive it is to the light, while a higher ISO number
increases the sensitivity of your camera. The component
within your camera that can change sensitivity is called
“image sensor” or simply “sensor”