This International Standard specifies a method of determining resolution by measuring the minimum size of detail recognizable in a processed microform. It describes the test patterns and ISO resolution test chart No. 2, and gives the method of expressing resolving power. ISO resolution test chart No. 2 is designed for use as part of a test target, as required in other International Standards for micrographics. This International Standard applies to the determination of the resolving power of a camera, film and processing combination used in a microfilming system or the resolution achieved in microforms therefrom. In this form it does not apply to the determination of the resolving power of microform readers, reader-printers or computer output microform (COM) imaging systems.