1. A three-dimensional imaging system comprising: a single image sensor; optics adapted to allow the single image sensor to capture images of an object in a scene along a common optical axis, wherein the optics are adapted to allow the single image sensor to capture the images such that they are focused to blur in different degrees without a change of objective lens focus or position of the object, wherein the optics comprise a beam splitter and an optical delay, the optical delay adapted to lengthen a beam path to the single image sensor; a computer processor connected with the single image sensor; and a non-transitory computer readable medium having instructions stored thereon, which, when executed cause the computer processor to: match elements from the images; and determine depth position for elements of the images by a comparison of differences in blurring for the elements.