HOW FILM IS MADE FOR YOUR CAMERA

[Music] [Applause] [Music] when you take a roll of film out of its sealed wrapper you're thinking about the pictures you'll take the ones you've missed the endless pleasure of the ones you have or perhaps you've wondered how film is made the familiar yellow paper serves to protect the actual film its feathered at the edge to roll tight against the sides of the spool and keep out the light these numbers are the ones that indicate how many pictures you've taken photographic film has four main layers first a protective layer then the pictures sensitive layer or film emulsion third a clear plastic supporting base and finally a bottom protective layer to keep out light reflections during exposure gelatin made from animal hides is the chief ingredient of the protective layers and the emulsion but it's silver in the emulsion that makes film sensitive to light to make the thick supporting layer or film base selected cotton or wood fibers are chemically treated to form a material composed of cellulose esters this is then fed into a machine to be chopped up prior to further processing [Music] from a story chopper the esters drop into a continuous mixer where chemicals are added to produce a clear thick syrup called dope really film bass in its liquid form [Music] the liquid is filtered before going into a blender to be thoroughly mixed [Music] next the film base passes through cooling pipes where it reaches a controlled temperature then through a hopper to spread out evenly on a huge revolving wheel once around and it is become solid enough to be stripped off finally the film base fred's its way through a maze of rollers to dry and is wound up into rolls [Music] this coding wheel is 18 feet high and more than five feet wide it can produce miles of film bass every day but the wheel is small compared to the coding machine of which it's apart this giant stands five stories high and is 75 feet long at any given time there may be a quarter of a mile of film base in the machine a skilled crew operating a set of complex controls keeps it running smoothly and the whole area must be kept hospital clean here a technician checks one of the sealed chambers the film base passes through in the chamber the base dries gradually and evenly [Music] at the wind-up end of the machine a footage counter indicates it's time to start a new role [Music] samples are quickly cut for testing in the quality control laboratory [Music] [Applause] changing roles during the continuous coding operation calls for real teamwork and precision it usually takes 30 seconds the full role is swung off the machine [Music] an identification record is attached as our plastic shields to protect the ends the role of film base is held in storage while the quality control department takes charge only when the test strips have been found to meet its rigid standards can a role be used in further film manufacturing steps [Music] the thickness of the film bass is measured it must be within 1 and 1/2 10 thousandths of an inch of standard a special light checks for scratches or abrasions [Music] the farm supplies another raw material purified gelatin processed from selected animal hides it is used in the outer protective layers and is also important in making the picture sensitive emulsion these sheets of gelatin are broken up in a hammer mill to ease handling meanwhile chemists are compounding the variety of ingredients that are needed by the emulsion makers [Music] here a solution is being stirred by a propeller whose speed is controlled to an exact number of revolutions per minute [Music] only a small part of the solution is needed in any one emulsion batch this is a weak supply being measured out in batch quantities [Music]