1. A range camera operable to determine distances to and reflectance for features of a scene that the range camera images, the range camera comprising: a light source operable to transmit light to illuminate a scene that the range camera images; a photosensor having light sensitive pixels; optics having an optical axis and optical center configured to receive light reflected from the transmitted light by features in the scene and image the reflected light on a plurality of the pixels, each of which plurality of pixels registers reflected light from a feature of the scene that the optics images on the pixel to provide a registered scene irradiance (RSI) for the feature; a calibration image comprising a registered calibration irradiance (RCI) for each of the light sensitive pixels that provides a measure of irradiance that the pixel registers responsive to light reflected from light transmitted by the light source by a region of a calibration surface having known shape, reflectance, and location that the range camera images on the pixel; and a controller operable to determine a reflectance for a feature of the scene imaged on a first pixel of the photosensor comprised in the plurality of pixels responsive to the RSI for the feature and an RCI for a region of the calibration surface imaged on a second pixel of the photosensor corresponding to the feature imaged on the first pixel.