Fogs: actual traces of the virtual are often light effects. Although we tend to think of the perceptual dimensions of light as clearly distinguishable and almost boringly familiar, they are not so docile on closer inspection. [...] The boundaries we set and distinctions we function by are habitual. According to many theorists of vision, they do not replace the infinitely complex perceptual fog that is our originary and abiding experience of light. They occur with them, alongside, in a parallel current or on a superposed abstract perceptual surface, in a perpetual state of emergence from the continuum of light-dimensions that one frustrated would-be tamer of visual anomaly termed “the brightness confound.” / The “brightness confound” can become a conscious percept, through a concerted effort of unlearning habits of seeing, or through a simple accident of attention. When it does, the confound is contagious. It strikes depth: three-dimensionality, argues the “ecological” school of perceptual theory, is an effect of complex differentials of surface lighting played out in ever-shifting proximities of shadow and color, reflectance and luminosity, illumination and
translucence (it is not, as traditional theories of perception would have it, the product of mysterious calculations of relative size and distance--as if the eyes could count). / Depth is a surface effect susceptible to the brightness confound. When it goes, so goes separable form. Not only do the relative size and distance of objects flutter, their boundaries blur. They cease to be separate figures, becoming not entirely localizable zones in a fuzzy continuum. In other words, they cease to be objects, becoming what they always were, in the beginning and in parallel: fluctuations. Visual runs. Experiential transition zones. The distinctions of habit fold back into the always accompanying level of the more-than- three-dimensioned light concurrence from which they emerged. The fixed boundaries and “constants” of our habitual perceptions are emergences from an experiential confound to which they can return, and must return. For they are not in the final analysis structural constants at all, but continually regenerated effects, predicated on the variation they follow and emerge from, as its perceptual arrest. They rest entirely on variation.