Canon AE-1 Instructions Manual page 59

Lens Signal Coupling
Aperture Signal Lever
This lever transmits the actual f/stop to
the exposure meter. I t
is
coupled to the
aperture ring.
Full Aperture Signal Pin
This pin transmits
a
signal indicating
the maximum aperture of the lens.
Automatic Aperture Lever
This lever closes down the aperture,
coupled with the stopped-down coupling
lever.
EE Switch Pin
This pin protrudes when the aperture ring
is locked at the
"A"
mark. In this position,
it
transmits a signal for
AE
photography.
R e S e ~ e Pin
This pin is designed for use with ac-
cessories that may be developed in the future.
~ ( g n a ~
f
Lever
Pin
l Pin