2. Aperture
• An aperture is a hole or an opening
through which light travels. More
specifically, the aperture of
an optical system is the opening
that determines the cone angle of
a bundle of rays that come to
a focus in the image plane.
3. Shutter Speed
• The camera's shutter
speed, the lens's brightness
together determine the
amount of light that
reaches the film or
sensor. Exposure value is a
single quantity that
accounts for the shutter
speed and the f-number.
4. ISO
• ISO is similar to film speed on
film cameras. Unlike aperture
and shutter speed, ISO doesn't
control how much light enters
the camera, but instead
controls how sensitive the
camera is to that light. The
lower the ISO, the less sensitive
the camera is. In other words, a
lower ISO will require more
light to properly expose a
picture than a higher ISO.
