INTRODUCTION TO FILM STUDIES

Introduction to Film Studies



Introduction to Film Studies

Introduction

Film consists of a series of light-sensitive chemicals on top of a layer of acetate. These chemicals change at two critical times: during exposure and processing.

Skylar (2002) mentions films can be divided into two types, indicated by the suffix on the film box: -chrome (slide film or reversal film, which can be made into high-quality prints/enlargements) or -color (print film, which includes a orange-colored negative in the case of color film, from which a color print is made; black and white film is made up of a black and white negative from which black and white prints are made). The higher the number on the box, the more sensitive the film. This number is standardized worldwide (Skylar, 2002).

Thus, ISO (International Standard Organization) 400 film is more sensitive to light than ISO 100 film. (Previously, ASA [American Standards Association] was used in the United States and DIN in Europe.) Thus, photographers use high-ISO (high-speed) film for low-light situations. Why not use high-speed film all the time? Unfortunately, higher-speed film is grainier. Larger film crystals are more sensitive to light, but the clumping of these crystals (grain) shows as dots, creating a kind of "speckled" effect in large enlargements (11"x14" or greater).

Discussion

Color film is made possible because the continuous spectrum that makes up white light can be analyzed into three equally spaced wavelengths: red, green and blue. Color film has three layers of emulsion, each layer sensitive to red, green or blue. Slide and print film are essentially the same; the difference occurs during processing; after the negative images have been processed, the film is briefly exposed (either chemically or with light) so that the silver compounds that had remained untouched now form reverse positive images (Skylar, 2002).

A second color development is then given. During this stage, the developer oxidizes and combines with other compounds in the emulsions to produce complementary colored dyes in the positive areas of each layer. At this stage, the three layers of film each contain a silver negative image (which is not needed) and a positive color image. After the silver is bleached out, three complementary color images are left in the layers which, when held against the light, give the effect of the original subject colors (Thompson, 1998).

Your eye/brain automatically compensates for differences in color. Film does not. The colors of available light vary greatly. Color "temperature," as this is known, is measured by degrees Kelvin. Professional photographers concerned about precise color temperature--especially in the studio--will use a color meter to measure this color. Lower color temperatures are associated with longer, redder wavelengths, the higher ones with shorter wavelengths that are associated with blue. On the Kelvin scale, candlelight measures at about 2,000 degrees K., most table lamps at about 2500 degrees K., photoflood lamps are around 3200 K., and noon daylight is about 5400 K. Flash is color-balanced for noon daylight (Thompson, 1998).

Of course, outdoor daylight conditions vary ...