2. Aperture
An aperture is a hole or an opening through
which light travels. If an aperture is wide
then the image will have a sharper focus
only for rays with a certain focal length.
This means that there will be an object that
it’s more sharper and the background
could be blurred. This is called depth of
field and this means the distance between
the nearest and farthest objects in a scene
that appear acceptably sharp in an image.
The aperture also determines how many of
the incoming rays are actually admitted
and how much light reaches the image
plane (the narrower the aperture, the
darker the image for a given exposure
time).
Aperture is also called the f-number. The
larger f-number is smaller opening.
3. Using a 18-55mm lens I thought I'd see how some real narrow D.O.F. compares with real wide
D.O.F.
F-Stop: f/36
F-Stop: f/11
F-Stop: f/5.6
I have changed the f-stop (aperture) when taking these images. As you can see they are very different. On
the left, it shows it is over exposed because there is not enough light. On the right, you can see that it is very
dark because I let the light in too much.
4. Shutter Speed
Shutter Speed is a setting on your
camera which controls the length of
time the shutter is open, allowing
light through the lens to the sensor
inside your camera. Shutter speeds
can go from very small fractions of a
second, to several seconds long on
most cameras. You will need more
time to expose the image when there
is less light available and, you will
need less time to expose the image
when there is more light available.
5. ISO
ISO stands for International
Organisation for Standardization. The
ISO setting on your camera is
something that has carried over from
film. ISO deals with the cameras
sensitivity to light
The higher the number, the more
sensitive to light the film is. The
lower the number, the less sensitive
the camera is to light. The ISO bit is
from the standards for film
sensitivity, and the number refers to
it’s rating.
