APPLY THE FUNDAMENTALS OF EXPOSURE AND FOCUSING
Calculate, determine, identify, and select the methods and the application
of the fundamentals of exposure and focusing.
Given information about the light sensitivity of film, common types of
Demonstrate competency of the task skills and knowledge by responding to the
multiple-choice test covering fundamentals of exposure and focusing.
TM 11-401, TM 11-401-1, TM 11-6720-253-10
Learning Event 1: DETERMINE THE LIGHT SENSITIVITY OF FILM
1. Exposure depends on the intensity of the light and the amount of time
the light exposes light sensitive material.
Light sensitive material
consists of silver halides bonded in gelatin called the emulsion.
emulsion layer is supported by a base. The base material is made of either
film, glass or paper.
2. Photographic film comes in many different sizes, types, and formats.
All films are assigned a numerical value indicating its sensitivity to
This numerical value is referred to as "ISO" (International
Standards Organization). ISO is a numerical value indicating an emulsion's
specific degree of sensitivity to light, referred to as the film speed.
a. The most commonly used ISO numbers range from 25 to 400. The higher
the number the more sensitive the film, which means less light is needed for
The lower the number the less sensitive the film, which
requires more light for proper exposure.
b. For convenience, the ISO numbers are usually classified into three