Tokina BH-725 T480420 User Manual
Product codes
T480420
25
Depth of Field
When you focus on a subject, there is part of the subject that is in
focus and parts in front and behind which are not in focus. This
range in which the object is seen to be sharply in focus is called the
depth of field. If the focal length is kept the same, the depth of field
gets deeper (the range in which the subject is sharp gets wider) as
the aperture is stopped down, and it gets shallower (the range
in which the subject is sharp gets narrower) as the
aperture is opened. Even when the aperture stop is the same, the
depth of field gets shallower as the subject distance gets shorter,
and deeper as the subject gets further away. Furthermore the depth
of field is deeper with a short focal length wide angle lens, and
shallower with a long focal length telephoto lens.
focus and parts in front and behind which are not in focus. This
range in which the object is seen to be sharply in focus is called the
depth of field. If the focal length is kept the same, the depth of field
gets deeper (the range in which the subject is sharp gets wider) as
the aperture is stopped down, and it gets shallower (the range
in which the subject is sharp gets narrower) as the
aperture is opened. Even when the aperture stop is the same, the
depth of field gets shallower as the subject distance gets shorter,
and deeper as the subject gets further away. Furthermore the depth
of field is deeper with a short focal length wide angle lens, and
shallower with a long focal length telephoto lens.
Perspective
Perspective is the visual effect of moving a subject which is in the
foreground closer to or further from the background. If you take
photographs with lenses of different focal length while keeping the
size of the subject in the foreground constant, the background
appears to be further away and the sense of perspective is
exaggerated with a short focal length wide angle lens. With a long
focal length telephoto lens, the background appears to be closer to
the subject and the sense of perspective is lessened. You can
greatly change the feeling of presence even with the same subject
by using this sense of perspective.
foreground closer to or further from the background. If you take
photographs with lenses of different focal length while keeping the
size of the subject in the foreground constant, the background
appears to be further away and the sense of perspective is
exaggerated with a short focal length wide angle lens. With a long
focal length telephoto lens, the background appears to be closer to
the subject and the sense of perspective is lessened. You can
greatly change the feeling of presence even with the same subject
by using this sense of perspective.
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