IS0被要求开发一种测量速度的方法 以及黑白负片拍摄过程的平均梯度 因为在航空摄影中使用的组合 各种现有标准的不相容性；目的是 创建一个包含以下内容的国际标准: 这些标准最重要的特点。

IS0 was requested to develop a method for measuring speed and average gradient of black-and-white negative camera filmprocess combinations used in aerial photography because of the incompatability of various existing standards; the aim being to create an International Standard that would incorporate the most important features of these standards.