Canon AE-1 Instructions Manual page 28

Shutter Button and Shutter Lock
The shutter release button is designed to
function as the main switch of the camera to
activate the AE meter and shutter operation.
The shutter has a magnetic release, so the
meter can be read by pressing the shutter
button halfway with light pressure. By de-
pressing it further, the shutter will be released.
The magnetic release shutter button enables
faster metering for shooting in succession than
the mechanical release method does. There is
also less chance for camera shake.
shutter release button i s turned to the "L"
position, the shutter button will be locked to
prevent unintentional shutter release. Keep
the shutter release button locked while
carrying the camera to prevent film waste.
When the power level of the battery is
insufficient,
a
safety mechanism will keep the
shutter from being released.
Frame Counter
The frame counter
i s
an additive type
which counts one frame every time the film
advance lever winds the film. When the
camera's back cover
is
opened, the frame
counter automatically resets itself to the "S'
position.
While rewinding film, the frame counter
counts back the frame numbers. The starting
position
"S". 0,
and the even numbers
2
to 38
are displayed by the counter. Numbers 20 and
36 are marked in orange to call your attention
to the end of film cartridges such a s are today
commercially available. The frame counter
cannot count higher than 38.