Cinematographic depth of field calculator - gives field depth for several predetermined valves of diffusion circles

摘要

The field depth calculator has one or several distance scales for use with one or several different objectives classes, for example fixed focal objectives and variable focal objectives; a focal scale (20) associated with a diaphragm scale (21) and an index system (23, 24) designed so that the two latter scales, after being adjusted with respect to each other, coincide the focal value of the objective used with the chosen diaphragm opening. It is then sufficient to bring an index opposite the focal distance in order to read on the distance scales, opposite the two other indexes, the field depth (for a given diffusion circle) corresponding to the class and the objective focal length, as well as the chosen diaphragm opening.