The Basics Of Exposure - Canon A-1 Instructions Manual

Memo Holder
The back cover of this camera is provided
with a me mo holder. Once you have loaded
the film and sel the ASA, it is very useful to
tear off the end of the film b ox and insert it
into this memo holder as a constant re-
minder of the typ e o f film in use. Add other
information as you - like.
•
The Basics of Exposure
This section contains some terms a nd
d efinitions which will b e used throughout
this instruction booklet.
The amount of exposure is a matter not only
of
the
amount of
ligh t
allowed
to strike
the film but also of the am o unt of time
the light is allowed to strike the film. The
camera has two mechanisms to control
exposure, the diaphragm and the shutter.
T he diaphragm consists of blades which
open and close to certain size openings
ca!Jed a pertures. The size of the aperture
d eterm ines the amount of light which will
fall on the film. T h e various size ape r tures
are indicated by a set series of numbers
called f/stops or f/numbers. E ach f/stop
represents some amoun t of light that is
allowed to pass through the lens. The smaller
numbers are called large f/s tops while the
larger numbers are called small f/stops .
T his is because the larger numbers represent
-30-
smaller apertures and allow Jess light to pass