Canon AE-1 Manual page 15

Frame Counter
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 depressing 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. 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 as are
today commercially available. The frame counter cannot count higher than 38.
Operation for General Photography The AE-1 is an Automatic Exposure camera with a
shutter speed priority system which electronically controls the aperture opening for the given
shutter speed to ensure the optimum exposure. Canon's shutter speed priority system has been
adopted by this camera in the idea that a photograph is an instant snatched from elapsing time.
The shutter speed priority system is ideal for catching fast-moving subjects, especially at the
decisive moment. Even most of the models in Canon's EOS System of AF cameras have this
shooting mode a standard feature. Furthermore, the shutter speed priority system allows you
to control image blur at will and to emphasize the movement of the subject. For action or
other such situations, you can realize all photographic aspirations.
Setting the Shutter Speed The shutter dial controls the length of time that light is allowed to
reach the film. On the shutter speed dial, shutter speeds from 1/1000 to "B" are marked in
white, while the 2-second speed is marked in orange. Each shutter speed gradation is twice or
approximately twice the preceding speed, beginning with 1/1000 sec. (1000).
The frame counter is 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.
Thus, the light reaching the film at 1/250 second is half the light
reaching it at 1/125. The numbers on the shutter speed scale
represent the corresponding fraction of a second (125=1/125),
with the exception of 1 and 2 (marked in orange) which stand for
1 and 2 seconds respectively.