DEPTH OF FIELD Depth
of
field refers
to
a
zone
within which blur (or lack
of
definition) will be negligible
and
everything
can be
accepted
as
being in sharp focus.
Depth
of
field
extends
a greater distance
behind
the
subject
in
focus
than
in
front
. It
depends
on
two
factors
-
reproduction
ratio
and
aperture.
The
smaller
the
aperture
and
the
greater
the
reproduction
ratio,
the
greater
the
depth
of
field.
By
carefully considering
the
desired pers-
pective and
reproduction
ratio, as well as available f-stops, full
control
of
the
depth
of
field
is
achievable.
Depth-of-field scale
The
depth
of
field can be read
from
the
color-coded scale
engraved
on
the
lens.
The
pairs
of
colored lines
correspond
to
f/numbers
of
the
same color.
To
find
the
depth
of
field
at
a
particular
aperture,
first
focus
on
the
subject.
Then
check
the
numbers
on
the
distance scale
opposite
the colored lines
which
correspond
to
the
color
of
aperture
10
find
the
depth
of
field
at
that
aperture.
For
example
,
f/16
on
the
aperture
ring
of
the
50
mm
f/l.4
lens
is
blue.
With
the
lens
prefocused
at
17
feet
(5
m)
the
numbers
on
the
distance
scale
opposite
the
blue lines
show
that
the
depth
of
field
extends
from
9
feet
to
infinity
(00).
Remember that smaller apertures, although rendering a greater
depth
of
field,"
require slower shutter speeds. Consider both
factors carefully before shooting, and always focus accurately.
Lens
at
f/2
small
depth
of
field
Lens
at
f/11 larger
depth
of
field
47