Specifications

the AE-1 Program. The usual one is by using the depth-of-field scale on the lens.
This is a scale of f/stops repeated on each side of the distance index.
1. First focus. Then press the shutter button halfway and note
which number appears in the viewfinder. Find the two f-stops on
the depth-of-field scale which correspond to that number. 2. Draw
imaginary lines from those two numbers to the distance scale. The
effective depth of field lies between those two distances.
You can roughly check the depth of field visually with an FD lens as follows:
1. Make sure the film has been completely advanced.
2. Press the shutter button halfway to find out which number is displayed in the
viewfinder.
3. Then press in the AE lock pin and turn the aperture ring to that number. Note: As a
reminder that the lens is off "A" the "M" will light up in the viewfinder when you press the shutter button
halfway.
4. Push in the stop-down lever until it locks. Now, just by looking at your subject
through the viewfinder, you can see the range of sharp focus.
5. After checking the depth of field, unlock the stop-down lever.
Now turn the aperture ring to the smallest number. Then turn it to
the largest number, press the AE lock pin and return the aperture
ring to "A."
Caution: It is NOT possible to push in the
stop-down lever when an FD lens is set at
"A".
Do not push in the stop-down lever before you advance the film or the diaphragm will
close down only as far as the aperture used for the previous exposure.
Warning: When an FD lens is mounted DIRECTLY on the camera (with no accessories between),
NEVER take a shot before releasing the stopdown lever or exposure may be incorrect. And unless you
want to make an exposure correction, return the aperture ring to "A" before shooting.