when a certain degree of balance is achieved in an optical reaction, and the effects of graphical resonance are allowed to emerge, a curious pattern of lines will develop without apparent cause. In some cases, lines formed during reactive events can be explained by the visual properties of the projection surface itself, in the vicinity of the origin or the striata. This might seem to explain their existence entirely except for the fact that the technique of acquiring striation effects with video feedback is much easier when the projection surface is evenly-toned and perfectly flat.
in larger optical fields, all parts of the human figure become reactive, and even more so within a studio “light stage” setting. Human skin is a highly optically reactive surface that allows light to filter through many layers before reflecting back. While the light bounces within the more transparent outer layers of epidermis, unexpected colors may be picked up — the blue of a nearby vein for example — that can be sensed by the camera and amplified by the projection system.
the uniqueness of each person’s physical appearance is a guarantee that every portrait reaction will be unique in its expression from moment to moment. Subtle movements of the eyes and mouth, and even more subtle elements of reflectivity, texture and color, all combine to form an optical “echo chamber” which resonates at each individual’s harmonic spectrum. Rather than resonating on acoustic frequencies however, optical resonance is more about the geometry of each person’s physical presence.
using video electronics equipment in ways that are consistent with their design — but combined in ways that were never before imagined — allows the creation of unpredictable emergent properties. With some level of control, it is possible to create long sequences of video which feeds upon itself frame by frame, uncovering graphical forms that are unique from one moment to the next yet exhibiting a consistent graphical signature that almost resembles a form of aesthetic style. Continuous optical reactions operate at a rate of just under 30 frames per second, and sometimes separate simultaneous reactions interleave the frames like alternate pages in a book.
caused when the angle between the focal path of the video camera is not coincident with the focal path of the video projector. If the lenses are aligned vertically, a variable reaction field is produced within which all points in the space will exhibit optical flux in a different direction. Generally speaking however, downward vertical shift increases within parts of the field closest to the reactor setup, and upward vertical drift will occur for surfaces positioned beyond the intersection of the focal paths.
referring to either the extraction or injection of energy into a reactive system, to either decrease or increase the reaction’s core tendencies, respectively. When using these terms the changes to the reactive system being described are always in terms of the amount of energy in the system, and not the amount of information contained within it. Though damping may lead to an apparent loss of information and amplification seems to add to or at least change the information in some way, the terms only refer to the change in the amount of energy in the system.
a non-reactive optical field state that is characterized by a pattern that is repeated many times. With ever greater separation between each iteration in an optical field, there is ever less potential to begin or sustain a recursive interaction. Strictly speaking, staggered reflections fit within the overall definition of optical reactions because the content of each frame cycle is dependent on that which occurred in the past. However the greater the distance between the reflected images, the less likely that there will be sustained interactions with the past reflections.
in terms of the dynamics of a reactive system, if the reaction is not perfectly static, then it is experiencing either expansion or contraction. This implies that when the tendencies of either expansion or contraction continue to their extremes, diffusion and compression will occur, respectively. In optical reactions, the tendencies to either expand or contract can give the illusion of heading into or away from a tunnel, or across some abstract terrain. Both epansion and contraction will result in the loss of graphical information in optical systems, and therefore require a continuous signal feed that is strong enough to overcome the losses.
the practice of interacting with an optical field with the body in some way, either in stationary poses or with motion, to create some desired expressive effect in performance. The existence of one or more optical fields in a performance area adds greatly to the expressive potential of the space, even though the background will typically be a light-absorbing black backdrop. Since every part of an optical field has different properties, the performer is able to find those areas that produce the most desired colors and patterns on their costumes and bare skin, mostly through improvisation rather than through deliberate choreography.
the condition caused by the proper alignment of video camera and video projector, connected in such a way that the projection is being fed by the camera that in turn is pointed directly at the surface being projected upon. The resulting colors and graphical entities are emergent effects that happen in some part due to the optical properties of camera and projector lenses, but to a greater extent on signal amplification and image enhancement provided by digital electronics gear. Optical reactivity is therefore a phenomenon that requires technologically advanced components and could not possibly exist in nature.