Minolta X-700 - Manual (Page 44)

DEPTH OF F I E L D
The range behind and in front of the focused
distance within which the image appears accepta-
bly sharp is called the depth of field.
It extends a greater distance behind the focused
distance (usually about 1/3 in front, 2/3 behind)
and is determined by three factors: the aperture,
the distance at which the lens is focused, and the
focal length of the lens. As illustrated by shaded
trees above, depth of field increases as the lens is
stopped down (e.g., f/1.7 to f/22) and becomes
greater the farther from the camera the lens is
focused. It decreases as the lens is opened up (e.g.,
f/22 to f/1.7) and the closer the lens is focused.
Depth of field is greater for short-focal-length
lenses than for telephotos at the same focused
distance and aperture. It is at its least for any given
lens in normal mounting when the lens is at
maximum aperture (as when metering and focusing
normally with Minolta MD or MC lenses) and at
minimum focusing distance.
4 2
focused distance
FOCAL LENGTH
Focused distance
FOCUSED DISTANCE
Focused distance
APERTURE