Basic Photography Course

Figure 13-1.Basic components of a motion-picture camera.

shock and prevent the film from breaking (fig.

The shutter in most motion-picture cameras is a

focal plane type and is called a rotary disk shutter. A
rotary disk shutter is a disk that has a segment cut out,
causing the shutter to have a light and dark cycle as it
rotates. Exposure is made when the cutout segment of
the shutter passes in front of the film. The film is
advanced during the dark cycle (fig. 13-2).

A motion-picture camera is used to photograph

action in a rapid succession of still pictures on a long
strip of film. Each picture area on a motion-picture film
is called a frame, and the speed that the camera is
operated is called frames per second (fps). The standard
operating speed for 16mm cameras is 24 fps. When the
camera operating speed and the rate of projection are the
same, the action looks normal; therefore, the standard
projection speed is also 24 fps. However, it is possible,
and sometimes desirable, to make motion pictures at a
slower or faster rate than 24 fps. You may do this to
either slow down or speed up the action on the screen.
To portray a subject in slow motion, you operate the

camera at a speed faster than the standard 24 fps, but

keep the projector at the standard speed. To portray a
subject in fast motion, you operate the camera at a speed
slower than 24 fps, and the film is projected at 24 fps.
All changes to the portrayal of normal subject motion
should be done by adjusting the camera speed, not the
movie projector.

Camera speeds in the thousands of frames per

second are used in scientific and experimental research

to measure and observe such things as the fall of liquids,
the speed of objects in flight, and the bursting
characteristics of objects. When films shot at very fast

fps rates are projected at 24 fps, the illusion of subject
motion on the screen is slowed down considerably. At
these speeds the viewer can study details of the subject
matter and obtain research data.

Motion-picture cameras are classified according to

the size (width) of the film they use. The most common

motion-picture film sizes are as follows: 8mm, super 8,

16mm, and 35mm. In the Navy today, motion-picture

film has almost been completely replaced with video
film; however, Hollywood productions still use
motion-picture film as large as 70mm.

Lenses used in motion pictures are basically the

same as lenses for still photography; therefore, the
information on optics presented in chapter 1 also applies
to motion-picture camera lenses. The standard or normal
focal length lens for a 16mm camera is 1 inch (25mm).
Longer or shorter focal length lenses should be
considered as long focal length (telephoto) or
wide-angle lenses, respectively, depending on what size
film is used. A long focal length lens for 16mm film is
38mm or longer. A wide-angle focal length lens for this
camera is 13mm-17mm. Table 13-1 illustrates some
typical camera and lens combinations.

FILTERS

With one exception, the use of filters for motion

pictures is the same as for still photography. The effects
that filters produce on motion-picture film emulsions are
the same as the effects they produce on still
photographic film emulsions. The one exception is the
use of a polarizing filter. Camera panning should be

avoided because variable darkening of the image results.

The information on filters presented in chapter 3 applies
to motion-picture photography as well as still
photography.

13-2

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Basic Photography Course

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DOFMaster for Windows On-line Depth of Field Calculator DOFMaster for Mobile Devices On-line Depth of Field Table Hyperfocal Distance Chart Articles FAQ Recommended Books Support Contact Links Home As an Amazon Associate I earn from qualifying purchases.	contents <- previous page next page -> Figure 13-1.Basic components of a motion-picture camera. Figure 13-2.Rotary shutter. shock and prevent the film from breaking (fig. 13-1). The shutter in most motion-picture cameras is a focal plane type and is called a rotary disk shutter. A rotary disk shutter is a disk that has a segment cut out, causing the shutter to have a light and dark cycle as it rotates. Exposure is made when the cutout segment of the shutter passes in front of the film. The film is advanced during the dark cycle (fig. 13-2). A motion-picture camera is used to photograph action in a rapid succession of still pictures on a long strip of film. Each picture area on a motion-picture film is called a frame, and the speed that the camera is operated is called frames per second (fps). The standard operating speed for 16mm cameras is 24 fps. When the camera operating speed and the rate of projection are the same, the action looks normal; therefore, the standard projection speed is also 24 fps. However, it is possible, and sometimes desirable, to make motion pictures at a slower or faster rate than 24 fps. You may do this to either slow down or speed up the action on the screen. To portray a subject in slow motion, you operate the camera at a speed faster than the standard 24 fps, but keep the projector at the standard speed. To portray a subject in fast motion, you operate the camera at a speed slower than 24 fps, and the film is projected at 24 fps. All changes to the portrayal of normal subject motion should be done by adjusting the camera speed, not the movie projector. Camera speeds in the thousands of frames per second are used in scientific and experimental research to measure and observe such things as the fall of liquids, the speed of objects in flight, and the bursting characteristics of objects. When films shot at very fast fps rates are projected at 24 fps, the illusion of subject motion on the screen is slowed down considerably. At these speeds the viewer can study details of the subject matter and obtain research data. Motion-picture cameras are classified according to the size (width) of the film they use. The most common motion-picture film sizes are as follows: 8mm, super 8, 16mm, and 35mm. In the Navy today, motion-picture film has almost been completely replaced with video film; however, Hollywood productions still use motion-picture film as large as 70mm. Lenses used in motion pictures are basically the same as lenses for still photography; therefore, the information on optics presented in chapter 1 also applies to motion-picture camera lenses. The standard or normal focal length lens for a 16mm camera is 1 inch (25mm). Longer or shorter focal length lenses should be considered as long focal length (telephoto) or wide-angle lenses, respectively, depending on what size film is used. A long focal length lens for 16mm film is 38mm or longer. A wide-angle focal length lens for this camera is 13mm-17mm. Table 13-1 illustrates some typical camera and lens combinations. FILTERS With one exception, the use of filters for motion pictures is the same as for still photography. The effects that filters produce on motion-picture film emulsions are the same as the effects they produce on still photographic film emulsions. The one exception is the use of a polarizing filter. Camera panning should be avoided because variable darkening of the image results. The information on filters presented in chapter 3 applies to motion-picture photography as well as still photography. 13-2 contents Basic Photography Course <- previous page next page ->	As an Amazon Associate I earn from qualifying purchases.
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