Patent US 6,441,972

An optical assembly divides a single image into a plurality of images which are simultaneously projected onto a single sensor array. The optical assembly is arranged so that each of the plurality of images can be made to pass through a filter of a different type. For example a polarizing filter of a different orientation, or a filter which passes a different spectral band. In this way a single digital camera having a single chip sensor array can simultaneously receive multiple substantially identical images which have been acted on by different filters. This allows data capture from a single frame of a single camera to be used to perform stress analysis, or spectral analysis. This is particularly useful when high speed image capture is desired which contains stress or spectral data, because each frame captured from the sensor array contains multiple images which can be processed to obtain stress or spectral data.