Canon A-1 - Manual (Page 77)

factors remaining the same).
For example, comparing a 28mm lens
with a 50mm lens at the same aperture
and shooting distance, depth of field is
deeper with the 28mm lens.
{.Ч} The greater the shooting distance, the
deeper the depth of field (the other two
factors remaining the same).
For example, if the subject is photo­
graphed from three and then from seven
meters away, the zone of sharpness in
the foreground and background is great­
er at seven meters.
Another characteristic of depth of field
is that it is generally deeper in the back­
ground than in the foreground.
V\Tien depth of field is important in your
picture, it is best to control tlie aperture
directly using the aperture priority .\E
mode. Using a small aperture is great for
getting sharp overall focus in a landscape or
any other type of subject, but shallow depth
of field also has its merits. Using a relatively
large aperture will make your subject stand
out against its surroundings by blurring the
background. This is an especially successful
technique in portraiture and special effects.
There are ways to check the extent of depth
of field. For this information, please refer
to page 76.