136 Moving Images: Making Movies, Understanding Mediaactor, which is fi ve feet. You adjust the lens so that everything that is fi ve feet
from the camera is in exact focus. Th is is the plane of focus. Th e depth of fi eld
is the space in front of and behind that plane that is also in focus.
In a particular situation, the depth that is in focus may be one foot in
front of the person and two feet behind the person (since one third of the
full depth is always in front of the focus point and two thirds behind that
point). Th us, everything that is four feet from the camera to seven feet from
the camera will be in focus. Th is range of what is known as “acceptable focus”
is the depth of fi eld for that shot.
In fact, depth of fi eld can also be understood in relation to the function
of your eyes. Hold your fi nger directly in front of your face. If you look at a
distant object or surface—such as a wall—your view of your fi nger will be
out of focus. If you shift your focus to your fi nger, the view of the distant
object or surface will now be blurry. You are not able to keep both objects or
surfaces in focus at the same time because the natural depth of fi eld of your
eyes is not deep enough to do this.Pulling Focus
Depth of fi eld is aff ected by a number of factors including type of fi lm stock
used, distance between camera and subject, and f-stop setting on the lens. Th e
focal length of the lens is important: a wider lens has a greater depth of fi eld
and a long lens has a smaller depth of fi eld. Th is is why telephoto lenses are
used to shoot a distant person on a street in sharp focus with blurry-looking
crowds in front and behind the character.Figure 4-17 In this tight shot,
the cinematographer takes
advantage of a shallow depth
of fi eld. (Courtesy Kendelyn
Ouellette)Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).