ARRANGEMENT FOR THE EXPANSION OF THE DYNAMIC RANGE OF OPTICAL DEVICES

Light intensity levels are measured at various locations in a scene and light amplified and/or attenuated by a device interposed between the source of light and the light-sensitive surface having a limited dynamic range. By attenuating bright regions and/or amplifying weak regions, the dynamic range of light intensities of the scene is reduced, thus enabling the limited dynamic range device to be used with scenes having a larger light intensity dynamic range. In applying the method to the receiving side of a 3-D measurement system employing projected light, a simpler system results and problems associated with modifying the high energy projected light are avoided. Also, a greater range of measured object surface reflectance is accommodated.