Relative Depth from Binocular Vision Discussing the phenomenology of color constancy led us to consider something new about visual perception. Besides simply measuring patterns of light with the various parts of your visual system, you also use those patterns of light to make inferences about the light sources, objects and surfaces in the world that produced them. In the case of color constancy, this meant thinking about how we might observe the pattern of light coming from an object or surface and use that to make a guess about its reflectance and the illumination shining on it. The former property should be a stable property of the object, while the latter might change under different conditions. We saw that there were techniques for estimating the reflectance of an object, but these relied on making assumptions about the world that might not always be true. In general, this is going to be the case as we continue to think about how we can recover properties of the world from pa