Kinetic Pictorial Art with Sun Spectra: My Heliochromic System

Abstract

I had decided early in the project to employ dispersed sunbeams to produce colors rather than to utilize light produced by other sources. (The use of electric lights in kinetic art has been discussed by numerous artists in past issues of Leonardo [ 1].) The reason was that not only does sunlight possess visible radiation of essentially all wavelengths, but it can be received in intensity limited only by the optical equipment used. Direct sunbeams from the Sun in a clear sky are required to produce a luminous range of saturated colors, of which a rainbow is only a pale example. Not even a color photograph can present the high saturation of the colors produced by the solar spectrum. P. K. Hoenich used sunlight in combination with filters to produce colored images on walls, but the saturation of the colors were limited by the use of filters [2]. In his more recent Robot Projector, sunlight passes through glass prisms as well as through colored filters and also is reflected from polished surfaces to produce images on an opaque mat white surface [3]. My Heliochromic System consists of four parts: (1) a heliostat (Fig. 1), (2) a set of prisms (Fig. 2), (3) a parabolic mirror and (4) a Heliochromic Chamber. The heliostat is an instrument that by means of an automatically controlled flat mirror reflects a sunbeam in a prescribed direction, in this case to a set of prisms. The inclination of the mirror is adjusted on what in astronomy is called equatorial mounting. To do this one must take into account the latitude for each particular location of an installation.