Section 2 Shooting
290
Copyright Goodheart-Willcox Co., Inc.
When working with a depth of field
measured in units as small as tenths of a
millimeter or thousandths of an inch, critical
focusing and a sturdy tripod are essential. To
eliminate camera movement from vibration, use
a cable release and mirror lock-up, if possible.
Manual focusing is almost always necessary to
get the desired fineness of focus.
A focusing rail, Figure 12-61, permits the
camera to be moved toward or away from the
subject in tiny increments to achieve precise focus.
It can be locked into position after focus is set. The
base of the rail unit mounts to the tripod, while the
camera is attached to the movable top slide.
A different technique can be employed if you
are using lower magnification under conditions
that permit hand-holding. For example, if you are
photographing flowers or insects at a 0.25× (1:4)
magnification and using flash or bright sunlight
as illumination, your depth of field at f/16 would
be just over 3/4″. In this situation, many nature
photographers would focus on the desired area of
the subject, and then use small body movements
to adjust placement of the plane of focus,
Figure 12-62.
Working Distance
Working distance is the amount of space
between the front of the lens and the subject.
A working distance that is too short can block
natural light, placing the subject in shadow and
making it virtually impossible to use artificial
light. Also, animals and insects have a comfort
zone—moving closer than the invisible border of
that zone will cause them to flee.
The key to working distance is the focal
length of the lens. The longer the focal length,
the farther you can be from the subject while
retaining the same magnification. The distances
are proportional, Figure 12-63. If you fill the
frame with your subject using a 50 mm lens
at a lens-to-subject distance of 6″, switching
to a 100 mm lens allows you to double that
distance to 12″ while keeping the same image
size. If the image size is kept the same and the
same f-stop is used, no change in depth of field
Kirk Enterprises
Figure 12-61. Focusing rail.
Jack Klasey/Goodheart-Willcox Publisher
Figure 12-62. To capture this close-up of a bumblebee,
the photographer was able to shift the plane of focus by
using body movement.
Goodheart-Willcox Publisher
Figure 12-63. A longer focal length permits you to gain
working distance while keeping the subject image the
same size.
50 mm
100 mm
Working distance
Working distance
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Section 2 Shooting
290
Copyright Goodheart-Willcox Co., Inc.
When working with a depth of field
measured in units as small as tenths of a
millimeter or thousandths of an inch, critical
focusing and a sturdy tripod are essential. To
eliminate camera movement from vibration, use
a cable release and mirror lock-up, if possible.
Manual focusing is almost always necessary to
get the desired fineness of focus.
A focusing rail, Figure 12-61, permits the
camera to be moved toward or away from the
subject in tiny increments to achieve precise focus.
It can be locked into position after focus is set. The
base of the rail unit mounts to the tripod, while the
camera is attached to the movable top slide.
A different technique can be employed if you
are using lower magnification under conditions
that permit hand-holding. For example, if you are
photographing flowers or insects at a 0.25× (1:4)
magnification and using flash or bright sunlight
as illumination, your depth of field at f/16 would
be just over 3/4″. In this situation, many nature
photographers would focus on the desired area of
the subject, and then use small body movements
to adjust placement of the plane of focus,
Figure 12-62.
Working Distance
Working distance is the amount of space
between the front of the lens and the subject.
A working distance that is too short can block
natural light, placing the subject in shadow and
making it virtually impossible to use artificial
light. Also, animals and insects have a comfort
zone—moving closer than the invisible border of
that zone will cause them to flee.
The key to working distance is the focal
length of the lens. The longer the focal length,
the farther you can be from the subject while
retaining the same magnification. The distances
are proportional, Figure 12-63. If you fill the
frame with your subject using a 50 mm lens
at a lens-to-subject distance of 6″, switching
to a 100 mm lens allows you to double that
distance to 12″ while keeping the same image
size. If the image size is kept the same and the
same f-stop is used, no change in depth of field
Kirk Enterprises
Figure 12-61. Focusing rail.
Jack Klasey/Goodheart-Willcox Publisher
Figure 12-62. To capture this close-up of a bumblebee,
the photographer was able to shift the plane of focus by
using body movement.
Goodheart-Willcox Publisher
Figure 12-63. A longer focal length permits you to gain
working distance while keeping the subject image the
same size.
50 mm
100 mm
Working distance
Working distance

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