Canon AE-1 PROGRAM Instructions Manual page 9

To mount the lens, first align
the red positioning point on
the lens with the red dot above
the camera mount as illus-
trated .
If your camera looks like this , with
a red dot showing inside the
camera mount, do not mount the
lens yet; correct exposure cannot
be ensured if you do. To release
the stop-down lever, unfold and
lightly press it down so it pops
out. Then mount the lens. Leave
the stop-down lever as it is.
Then turn the lens in the di-
rection of the arrow until it
stops and the lens release but-
ton pops out with a click.
9
Make sure the lens release
button has popped out. Other-
wise, the lens will not work
properly. DO NOT press the
lens release button while
mounting or it may not pop
out.
When film is loaded, make sure
it is completely advanced to the
next frame before mounting the
lens.