Photo Calculator is a simple cross platform software for measuring the depth of field in an image.
Depth of field is the distance between the nearest and furthest parts of an image. Photo Calculator allows you to avoid what the developer calls "the circle of confusion" by selecting the exact resolution you want from a list and Photo Calculator works it out for you.
There is no DMG file with Photo Calculator. Installation of Photo Calculator requires you to double-click and drag the cam_mac folder to your applications folder from where can run it as a normal application. Once open, Photo Calculator simply requires you to configure the coordinates you require including Film Format, Units and Resolution and the results will be presented the moment you click "OK". There are no preferences or options however and Photo Calculator uses a generic Dock icon.
Photo Calculator is a very simple program that's low on aesthetics but high on functionality for photographers that need to measure depths of fields.