The light field camera with spatial multiplexing configuration enables to capture 4-dimensional data on 2-dimensional sensor. It creates 2D array of 2D images on a single sensor. Once certain conditions are fulfilled, it is possible to reconstruct the depth with single light field camera. Such measurement method has several advantages as well as several disadvantages. Currently, the most important problems are narrow measurement area and low light intensities. To overcome these obstacles, we propose augmented focused light field camera model which contains vignetting and image overlapping features included. The model is based on 2D ray tracing technique with first order optics and thin lens approximation. In this article, we state several properties which should be sufficient for the light field optical system design for depth reconstruction. This allows to describe every light field system configuration containing main lens, microlens arrays, stops and a sensor.