Canon AE-1 Instructions Manual page 14

Removal
from
Lens
1. Turn the cap counterclockwise until it
stops.
2 .
Pull the cap out.
Reattachment
1.
Align the arrow on the cap with the red
dot
a t
the rear of the lens.
2. In that position, apply slight pressure
to the cap and turn it clockwise until
it is tight.
Operation
with
an
FD lens
w h i c h has a
chrome Breech-lock
mount
r i n g
or
with
an F L lens:
Removal
from
Lens
1. Turn the lens' mount ring clockwise until
it stops.
2.
Pull the capout.
Once the rear cap is remved,the Breech-
lock mount ring
is
locked so that it cannot
be turned. (The diaphragm blades are also