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Figure 12-9.Keyboard of a Noritsu Model 1001 print processor
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Photography (Basic) - Introduction to photography and other graphic techniques
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CHAPTER 13 MOTION MEDIA Motion  media  has  gone  through  many  technical advances in the past several years. Portable motion- video  cameras  have  changed  from  cumbersome cameras  and  recording  packs  to  small  hand-held cameras. Reduced size, improved quality, and easier operation  has,  and  is  continuing  to  improve  and expand motion video in all areas of the Department of Defense.   Most   Navy   ships   have   closed   circuit television systems for information, entertainment, and educational purposes. Motion media is distributed easily   and   dominates   all   other   sources   of communication in today’s society. Because of this, the Navy uses this form of communication extensively to relay  information. The most common form of motion-media photog- raphy is video. Since the motion picture is the grand- father to the technology of motion media as we know it today, it is discussed briefly in this chapter. MOTION PICTURE The first fact regarding motion pictures is they do not move. Each image or frame of motion picture film is  a  separate,  still  photograph.  These  individual images or frames are normally recorded at a rate of 24 separate pictures per second. This rate can be varied to achieve certain effects. Since so little time passes between exposing one frame and the next, there is relatively  little  difference  between  pictures,  even when the subject moves rapidly. The illusion of motion in motion-picture photog- raphy is due to the natural characteristic of human vision. This characteristic of human vision is called persistence  of  vision.  Persistence  of  vision  was discovered by Peter Mark Roget, the author of the famous Thesaurus. The retina of the eye continues to perceive an image for a short period of time after the light  stimulus  representing  the  image  has  been removed. Usually, this “after image” lasts about 1/50 second, depending on the brightness of the image. In viewing a motion picture, the eye continues to perceive the fading image projected from one frame as it is replaced by the next frame, and so on. In effect, the images are momentarily superimposed in our vision, so any differences between them, however slight,   are   mentally   noted.   If   these   differences suggest  any  relative  change  in  subject  position,  the apparent   difference   is   mentally   interpreted   as motion. The mind translates this information into the logical deduction that whatever we are seeing on the movie screen must be moving. CAMERAS Since motion pictures are a series of still pictures, the motion-picture camera is basically the same as the still-picture camera. The primary difference is that it has   a   mechanism   for   taking   a   series   of   many photographs  in  rapid  succession  and  at  regular intervals on a ribbon of film. All cameras have the following four basic parts: a lighttight compartment, a lens or lenses, a shutter, and a film plane or pressure plate. The motion-picture camera has two additional basic features; the film drive and intermittent action. The   film   drive   mechanism   transports   the   film continually from a supply spool of unexposed film to a take-up spool of exposed film. This transport takes place by means of toothed, drive sprockets. The teeth of the drive sprockets engage the perforations along the edge of the film and move the film through the camera. The   intermittent   action   in   a   motion-picture camera is caused by a pulldown claw that advanced the film one frame at a time at the film gate. During one cycle of operation of a motion-picture camera, the following action takes place. The film is advanced  by  the  sprocket  drive  mechanism.  The pulldown claw or shuttle then advances the film one frame.  The  film  is  stopped  momentarily  and  the shutter revolves once, thereby making the exposure. The pulldown claw then moves the film to the next frame for exposure. Because the film moves in an intermittent  or  stop-and-go  manner,  it  becomes necessary to have a surplus or loops of film before and  after  the  pulldown  claw  to  help  take  up  the 13-1







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