1. A compact optical see-through system for a head worn display comprising: an optical system having telecentricity in an intermediary space for selectively blocking and selectively passing selected portions of a scene from original scene images to produce a modulated output, the optical system including: an objective lens having a focal point placed at an entrance pupil of the optical system to collect light from the original scene for imaging said original scene images onto said optical system; a polarizing structure including a polarizer and an x-cube prism adjacent to the objective lens for polarizing the original scene from the objective lens to produce a polarized intermediary image; a 3D real-time depth extraction system to determine an occlusion mask; a spatial light modulator for receiving and modulating the polarization of the intermediary image to produce the modulated image based on the occlusion mask; a microdisplay for displaying the virtual image, a light from the microdisplay being combined with a light from the spatial light modulator using the polarizing structure and reflecting the modulated intermediary image; and an eyepiece with a focal point placed to form an exit pupil of the optical system for mapping said modulated image back to said original scene images for viewing by a user wearing said see-through head worn display, wherein said see-through head worn display displays virtual objects while occluding real objects and real objects occluding virtual objects.