[iPhone God App] It was found using the Hyperfocal Calc actually

Hyperfocal Calc aka iFotobacus calculates the Hyperfocal distance for a given combination of focal length and aperture of the camera lens. The hyperfocal distance for a lens zoomed to a particular focal length is defined as the nearest distance of focus which maximizes the depth of field. In other words, when the camera is focused at the hyperfocal distance for the given aperture-focal length combination, everything from half distance as the hyperfocus distance to infinity will be recorded sharp in the photograph. Such knowledge is highly useful in landscape photography. Also when the main subject of interest is close to the camera and the details of landscape behind the subject are also desirable.

iFotobacus Features

1.Intuitive and simple interface
2.Nearly 2400+ popular still cameras in its database
3.Automatically saves user settings, you can start right where you left
4.Calculations for user chosen focus distance
5.US customary units and Metric units
6.In addition to hyperfocal distance, it also calculates near focus distance, far focus distance and depth of field.