1. A system for plenoptic photography, the system comprising: a) a lenslet array; b) a sensor element positioned at a distance from the lenslet array; and c) a field lens and focusing optics positioned between the lenslet array and the sensor element, wherein the field lens is configured to gather light refracted from the lenslet array, and the focusing optics is configured to focus the gathered light on to the sensor element, thereby forming a plurality of lenslet images on the sensor element, with each lenslet image corresponding to a lenslet in the lenslet array; wherein the position of the lenslet array relative to the field lens is adjustable.