Exposure - Canon AE-1 PROGRAM Instructions Manual

El-(eXam Ple)
Programmed AE
mode
either of
the two blink s
Use fl as h o r
higher ISO/
ASA rating
film ,
Shutter -speed priority AE mode : Wh en 2 sec ,
is set on the shutter speed selector dial and a
number equal to or smaller th an the len s' max i-
mum aperture blinks; or
Programmed AE mode: When the lens' ma x-
imum aperture blinks,
you can a) Use flash or other additional light ;
or
b) Use a film with a higher ISO/ ASA
rating ,
With the shutter button pressed halfway, a red " M "
LED 4 appears whenever you remove the aperture
ring of the lens from " A" or when yo u mount a non-
FD lens, See pp,
57 -58,
It warns you that exposure
will not be automatic,
41
14. Exposure
Taking a picture is a matter of letting light fall on
the film under controlled conditions, This is
called exposure, When you press the shutter
button, some blades (called a diaphragm) inside
the lens shift to form an opening called the aper-
ture, Almost simultaneously, the first shutter
curtain starts to move inside the camera, A
second shutter curtain follows it after a fixed
interval which you control with the shutter
speed selector dial. The amount of light that
exposes a frame depends on the shutter speed
and the size of the aperture,
For the same exposure, a change in the shutter
speed requires an equal and opposite change in
the aperture, The AE-l PROGRAM makes this