Display systems that utilize digital micro-mirror device (DMD) technology are finding wide application in the areas of projection systems for color display. The common name for such systems is digital light processing projection systems or DLP projection systems. The systems and methods described herein utilize the non-imaging light to monitor and calibrate the projected image since the high levels of illumination and extreme temperatures of the imaging light require careful attention to the manner of light collection. Light collection is accomplished in a waste gate area by a light collector, e.g., an optical fiber mat, and the collected light is communicated to an associated sensor. The technique is non-invasive and may be applied to existing designs with minimal modification.