In order for an image to be captured on film, it must be exposed to
light. The camera has two settings that control light, and they work
very similar to the human eye.
|The shutter blocks all light from exposing the film
UNTIL you press the button. Then it quickly opens and closes, giving
the film a brief flash of light.
You can control the length of
time the shutter remains open by setting the SHUTTER SPEED.
speeds = more light
shorter shutter speeds = less light
|Before light reaches film, it must pass through an
opening called an "Aperture". The aperture is like a pupil. You can
control the aperture by setting the "Aperture Opening", also known
as an F-Stop.
F-stops numbers = larger openings
larger openings =
Determines HOW LONG the shutter stays open.
||The longer exposures ( like 1 second ) give much
more light to the film than a 1/1000 of a second exposure. So even
though the number may look bigger, don't be deceived!
A half second exposure is ONE STOP
darker than a one second exposure.
A 1/125 exposure is TWO STOPS brighter than a 1/500 exposure.
A 1/1000 exposure is THREE STOPS darker than a 1/125 exposure.
Aperture Settings (F-Stops):
|Like the pupil in a human eye, the aperture on a
camera controls light.
It does so by closing up to restrict light,
and opening up to let it through.
moving from f16 to f8 is:
TWO STOPS brighter.
moving from f5.6 to f8 is:
ONE STOP darker
moving from f4 to f2.8 is:
ONE STOP brighter
Balancing Shutter and
Exposure is about different combinations of shutter and f-stop settings.
These combinations can drastically affect the finished picture. For
example, the following three pictures have been given an equal amount of
light, but the f-stop and shutter combinations make each one unique.
Take a stop, Give a stop..
Since f-stop and shutter are both measured in stops, keeping balance is
easy. If you take away 2 stops from the aperture, you can give 2 stops
back with the shutter and end up with the same exposure level.
The Red line is the correct exposure, any combination of
shutter speed and aperture will give the correct exposure.