The Complete Online Filmmaking Reference - Film Distribution ...

Film cameras
How Filmmaking Cameras Work
Movies don't move. A movie is a series of still pictures presented to the viewer so rapidly that the viewer's brain
is fooled into thinking the images are moving. The eye holds the image of one picture for a moment after it is no
longer shown until the next picture appears. This is called persistence of vision and allows movies to work.
Movies consist of 24 separate still photographs projected each second. This is just fast enough to generally
convince the eye that the images are alive and moving.
Cameras use a lens to focus the light rays coming from the scene onto a small rectangular area of film or, in the
case of video, onto an electronic circuit that is sensitive to light. In a film camera a shutter opens allowing light to
shine on the film for a moment, then the shutter closes and the film is advanced to the next frame by a claw
mechanism. Then the process repeats 1/24th of a second later. In a video camera light is gather by the electronic
circuit for a fraction of a second then the brightness and color values are read out of the circuit for processing
and writing to some form of memory.
Film formats
Film consists of light sensitive chemicals coated on a thin, clear cellulose acetate or other flexible plastic film. The
chemicals are color dyes and silver compounds (explaining the high cost of photographic film). Most high-budget,
professional films are still shot on 35mm color film stock. 35mm film has been the common format since the very
first movies.
When the film is processed it becomes a negative image of the original scene with the lightest areas of the
original scene represented as black on the film, and the darkest areas of the scene staying light and transparent
on the film. Colors are also reversed. A positive print has to be made from the negative in order to view the film
correctly.
16mm is a lower cost alternative but somewhat lower quality. A few filmmakers experiment with super-8mm but
the results don't hold up well in theater projection. All the world's theater projectors are 35mm so any other film
size will have to be enlarged and reprinted onto 35mm at some point if it is to be shown in theaters.
Film can be shot in a variety of rectangular shapes called aspect ratios. A movie's aspect ratio is given as a ratio
of the width of the frame divided by the height. The classic size of 35mm film and standard definition television is
a width of 4 units and a height of 3 units giving an aspect ratio of 1.33:1. This aspect ratio is often referred to as
Academy aperture after the Academy of Motion Picture Arts and Sciences which first defined and standardized it.
Although the Academy frame was standard for most of the early years of filmmaking a wider aspect ratio is now
preferred. In America the most common ratio is a 1.85:1 widescreen ratio. Most European films are shot with a
1.66:1 ratio making them not quite as wide as American films project for the same height. The film is shot on the
same 35mm film stock but the top and bottom of each frame is cropped by masking it off in the cameras and
projectors. High definition video uses an aspect ratio of 16 to 9 units, or 1.78:1 which is very close to 1.85:1
widescreenand makes a transfer to film possible with only a small amount of cropping.
Another popular format is anamorphic widescreen having an aspect ratio of 2.35:1. It is sometimes referred to as
scope after the trade name Cinemascope. Scope is also shot on the same 35mm stock and the extra wide aspect
ratio is achieved by a combination of cropping the top and bottom of the frame and using a special anamorphic
lenses which images the scene onto the film by squeezing the image more horizontally than vertically.
35mm cameras are generally very large, heavy and cumbersome pieces of equipment. They require substantial
tripods and dollies and several operators to use them. Some newer cameras are small and light enough to be
handheld or supported on a Steadicam, a support that is attached to an operator and keeps the camera steady
while the operator walks through the scene.
35mm production is worth it when the budget is large enough as non of the current video formats can quite equal
the quality.
A few productions are even shot using special 65mm or 70mm film and cameras. Films such as Lawrence of
Arabia and the popular IMAX films have startlingly rich and detailed images.
Film sound