If the doors of perception were cleansed

every thing would appear to man as it is, infinite.

For man has closed himself up,

till he sees all things thro' narrow chinks of his cavern.

William Blake, 1790

This posting is a little parable on the paucity of photorealism as a goal for graphical rendering, and a suggestion that the impressionists and expressionists were on to something.

Deep within the sun, tightly wound and highly compressed space-time gives itself up little by little; neighbouring nexus of hydrogen atoms entrain each other briefly to a higher energetic level in an exchange of quantum state quaintly named "the quantum wave function collapse". This quantum packet of exchange is the photon - not the ballistic luminous ping-pong ball of Descartes, but the elegant gradient flux of Maxwell.

The energy is exchanged for thousands of years until the wave function collapse couples an atom near the surface of the sun with an atom near you. The entrainment of this atom takes about 500 seconds; it occurs at the speed of light. Uncountably many wave function collapses couple an exchange of energy between the sun and atoms all around you, and so objects are illuminated.

As you bring your eyes to bear on an object, that cascade of energetic couplings begun in the sun entrains molecules making up the receptors in your eyes - the rods and cones are resonant structures tuned to entrain quickly to certain wavelengths of energy.

• At this point, we must briefly interrupt the journey of the photon to note that on the way to perception, this is the last moment when physical reality has any resemblance to a photograph or computer rendering. In fact, it now rapidly diverges; whereas the eye is intermediating an energetic exchange between the environment and the brain, a camera is inducing a chemical change on film (or an electrical exchange on a sensor) for the construction of an image. The constructed image will never have the same energetic response with the environment or the viewer, and will instead only mediate other secondary exchanges between other sources of energy, the paper (or monitor), and your eye. Almost all of the wonderful interplay and change over time of spectra, energy, and the nervous system are lost at this point, flattened to the limited response of silver hallide or a semiconductor's photo-electric charge.

The rods and cones resonate with the incoming energy, potentiating associated neurons; those neurons quiver at a threshold; when reached, they fire. These patterns of activation spread to neighbouring neurons in the retina, predisposing or inhibiting those neurons' sensitivities, and likewise, patterns of activation spread through the layers of the retina, where patterns, gradients, and tonic levels are categorized, organized, filtered, and passed through more levels of extraction until finally a highly refined signal train describing the patterns and meta-patterns of energetic interactions of rods and cones with the environment and neurons with each other are passed down the optic nerve.

The optic nerve feeds those through the layers of the portion of the thalamus dedicated to vision where yet more processing takes place, and finally the roving spotlight of attention in the occipital lobe stitches the information into a persistent overall model of the visual field.

The attentional spotlight emphasizes those visual features of interest, retains a model of things that must be noted but are not presently in the field of foveation, and provides signals of note, such as "I think the tiger is over there." Since the field of high resolution perception in the eye is so small, feedback to the eye is generated to saccade the gaze here and there to fill in the blanks.

Good artists, whether they be painters, directors, animators, or sleight of hand magicians understand the role of attention, and they guide the viewer through the doors of perception to achieve that activation in your mind that most closely makes you see, or most closely makes you to feel. Of course a photograph can be used to have this effect on the viewer, but it is not an intrinsic property of the eponymous photorealism, but rather a property of our perception and the subtle and wonderful fabric we weave between each other through our art.

- Nick Porcino

13 Oct. 2009