Minolta XG-1 - RELEASING THE SHUTTER

36
Depth of field
The distance behind and in front of the
focused distance within which the image ap-
pears
acceptable sharp is called the depth of
field.
It exte nds a greater distanc e behind the
focused distance than in front and is det er-
mined by three factors : the aperture size, the
distance at which the lens is focused, and the
focal le ngth of the lens in use. Depth of field
increases as the lens is stopped down (e .g., f/2
~~~i.l~~~
~~i ••• l~~
"
r--Fo cused distance--.j
to f/16) and becomes greater the farther from
the cam er a th e lens is focused. It decreases as
the lens is opened up (e .g. f/16 to f/ 2) and the
closer to the camera the lens is focused. Depth
of field is greater for s hort focal length lenses
than for te lephoto' s at the same focused dis-
tance 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 no r mally with Minolta MD- or
Me-type lenses) and at minimum focusing
distance.
Depth - of - field scale
The nea'r and far limits of acceptable sharp-
ness can be determined from the depth-of - field
scale on the lens barrel . With the lens focused at
a given point, the image w i ll be in satisfacto ry
focus from the nearer value to the farther value
on the distance scale ind ic ated by the depth -of-
field scale marks for the aperture to be used.
For example, if a 45mm lens is focus ed at