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blasted to provide afoil to the transparent , glassy and three-dimensional [3D] elements.) The horizontal and vertical diffractions were achieved merely by turning the hologram 90°. Given an in-line hologram, I knew of no simple lighting formula for acceptable playback. (The use of a separate reference beam has been suggested .) I saw the main problem as needing to ensure that people were not dazzled by the light source. In a full-scale version, my intention was that the sandblasted areas would provide translucent light barnes. The lighting experiments on the maquette, which were, of necessity, carried out in a variety of (sometimes informal) environments, produced some interesting and promising results . Excellent side lighting was achieved in a low-light situation, using diffuse daylight. In fact, the maquette responded exceptionally well to low light levels. The imagery in the holograms was activated by light from above and below as well as from horizontal light sources, and the imagery could be viewed from either side. The diffraction worked well in reflection, even lit by an ordinary domestic pearl lamp. In fact, the technique seems to respond to any available light source, however weak: torch, candle, oil lamp and moonlight; domestic and street 518 Abstracts lamps and fluorescent tubes; sunlight and diffuse daylight. Obviously the type oflight affects the quality ofthe image. The only lighting situation in which the hologram seems totally 'dead' is one in which it is viewed against a background of wholly unrelieved diffuse light, such as sky light. Even there, if a bird flew across the space behind the hologram, its dark silhouette would produce a flicker'of colour. These results suggest techniques by which holographic glass could be made to work in an architectural context . I did go on to make a full-size section for this maquette-2 X 1 m. The diffraction is bright enough, but I have not been able to analyse it, and, along with other maquettes and models, it remains 'work in (suspended ) progress'. In making Wavefonns, two objectives were achieved: the viewing ranges were as broad as could be wished, and even the small-scale maquette demanded that viewers move around to fully appreciate its visual properties. If appropriate lighting can be achieved, independent of mechanical and electronic controls (as seems possible), holographic glass, in which the images shift and change in a planned but unpredictable manner, would offer undeniable practical advantages in a permanent architectural structure. Fig. 2. Martin Richardson. This drawing illustrates a method of exhibiting rainbow holograms. The drawing was explained to, and understood by, the persons responsible for hanging the work in a gallery. DRAWING: PREPARATION FOR HOLOGRAPHY Martin Richardson, 22 Spencer Road, London W3 6DW, United Kingdom. Received 17January 1991. In spiteofeverythingI shallrise again: I will takeup mypencil, whichI have forsaken in mygreat discouragement, and I willgo on with mydrawing. -Vincent van Gogh, 24 September 1880 It has to be said that drawing or mark making is the origin of most, if not all, forms of creative design. In Western tradition, drawing has evolved into one of the lesser forms of art: as a sketch for a larger canvas, for example , or as a method ofvisual note taking . My attraction to drawing stems from its accuracy in communicating the kind of compositions developed through the process of three-dimensional (3D) spatial imaging via the holographic medium. When Henry Fox Talbot referred to photography as 'photogenic drawing ' in 1839 [2], it is said that many artists put down their pencils to take up the camera. Given that holography is far from being as convenient as photography, I find it necessary to pick up my pencil to design compositions that may take days to prepare in the holographic studio. I think of my drawings as working drawings-the first step in the process of creating a holographic artwork. Many of my drawings appear to be diagrams. Many appear to be sketches. Some are labelled with written notes-to remind myself during the recording stage of the predetermined positioning of subject matter or to provide instruction regarding reconstruction of an imagined scene in holographic form-or with shorthand notes and drawn descriptions that graphically clarify arrangements of subjects. The...

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