(A length of) film bearing greatly reduced photographs, as of books, newspapers, or documents, and which must be enlarged by projection for viewing.

缩影胶片(含有书籍、报纸、文件等物极度缩小照片的胶片，需藉幻灯机放大以供查阅)。

To make a microfilm of.

将...制成缩影胶片。