**4.1.1 Darkness**

Darkness, which has always has been a pictorial device of great importance in traditional media has also frequently been employed by artists to create ambiguities in optical holograms. Michael Baxandall in *Shadows and Enlightenment* pointed to an example of a drawing of a Roman soldier by Tiepolo in which the overall lighting pattern has nested within it smaller zones in which the lighting behaves in a completely different way (Baxandall 1995). This enables the viewer to make two possible interpretations as to where the leg of the soldier is located. This ambiguity as to the position of the leg engages the viewer in perceptual switching. In Margaret Benyon's, one- step laser transmission work *Hot Air*, 1970 laser transmission hologram 20 X 25cm, the beholder sees within one composition still – life objects, which display a full range of tonal values, and also a hand– shaped black void area. Similarly to the Tiepolo example, there is one overarching lighting arrangement of the objects in the scene, however, within this arrangement is the totally black hand, which is inconsistent with the overall pattern. The primacy of the artist's presence being registered through a negative rendering of their hand is immediately brought to mind, but in reverse, for the precise volumetric rendition of the hand instead creates a poignant sense of absence through the three-dimensionality of the trace.

The Visual Language of Holograms 341

The six panels of *Working Model One*, laser transmission holograms by Paula Dawson, each show a plaster frame straddled by a curved section of plaster cornice. The lighting of the overall scene of the plaster cornice frames seems consistent, however, as the viewer moves, a darkness, which cannot be ascribed to shadowing, also moves over the three-dimensional space of the curved piece of plaster. This unusual soft edged zone of darkness traveling in unpredictable ways through the image volume lends a sense of mystery. Dawson achieved this effect by applying the holo-diagram, a graphic invention by Nils Abramson for plotting physical zones of the repetition of laser coherence and incoherence (lightness and darkness) (Abramson, 1981). Abramson's application of the holo-diagram enabled him to avoid the dark zones and thereby record a large piece of machinery all in light with a short coherence

laser whereas Dawson intentionally located the zones of darkness in a different way.

manipulating this representational system:

**5. Reflection hologram – one and two step** 

artist (Benyon, 1994).

these two. As Pepper notes:

occupied "Box 1" (Pepper , 1989).

(holographic picture plane). Pepper explains the process:

In order for the interference pattern to be recorded as a hologram, all elements involved in the recording process including the optics and the subject must remain absolutely static throughout the duration of the exposure time. Unless a pulsed laser is used, a living hand cannot be static to the required extent. Benyon's effect was achieved by intensionally using the long exposute of a continuous wave laser to allow the stable inanimate objects to be successfully recorded as bright light forms and the living hand to not be recorded and therefore become dark. Darkness of a holographic subject is generally regarded as a mistake. Saxby's fault- finding chart proposes that the only way to get around the problem is to "use a more rigid subject" (Saxby, 1991). As Benyon points out in discovering means for

The physicist tries to get an approximation close to reality, to eliminate properties of the medium that distort, whereas it could be exactly those properties that make it unique to the

Andrew Pepper in his article *Holographic Space: A Generalised Definition*, conceptualizes the spaces available for the subject of a hologram as being box like, behind the picture plane "Box 1", in front of the holographic picture plane "Box 2"and then a third space which spans

When objects in the hologram are in a position between "Box 1" and "Box 2" they straddle the flat holographic plate. Because we know that a solid object cannot pass through a solid

The previous examples of HOE's were either "Box 1" Seth Riskin or " Box 2" Sally Weber. Similarly, one step laser transmission imagery of Margaret Benyon and Paula Dawson

Andrew Pepper's one-step optical reflection hologram protruding drawings are a perfect example of the opening of the third type of subject space, one that traverses the support

The drawing series was produced using a simple single beam Denisyuk system. The 'drawings' (isometric projections of a cube), were placed into the single reference beam, causing its shadow to fall onto the holographic plate, pass through it, and 'fall' onto the featureless white background situated behind the holographic plate. Once processed, the hologram was rotated around its horizontal axis so the shadow of the cube (originally visible behind the holographic plate) becomes visible as a pseudoscopic image, protruding out of the hologram and manifest in the space between the observer and the plate. The

holographic plate, we visually ignore the plate and are no longer confined by it.

Fig. 6. Margaret Benyon, *Hot Air*, 1970, laser transmission hologram, 20 X 25cm

Although the hand-shaped black hole in this hologram has little visual detail, it subjectively captures the essence of the hand, which was once there and stimulates questions about the owner of the invisible flesh…something beyond the 'object', something which is intangible and untouchable - the roots of an idea or conceptual improbability (Pepper, 2008).

Fig. 6. Margaret Benyon, *Hot Air*, 1970, laser transmission hologram, 20 X 25cm

and untouchable - the roots of an idea or conceptual improbability (Pepper, 2008).

Although the hand-shaped black hole in this hologram has little visual detail, it subjectively captures the essence of the hand, which was once there and stimulates questions about the owner of the invisible flesh…something beyond the 'object', something which is intangible The six panels of *Working Model One*, laser transmission holograms by Paula Dawson, each show a plaster frame straddled by a curved section of plaster cornice. The lighting of the overall scene of the plaster cornice frames seems consistent, however, as the viewer moves, a darkness, which cannot be ascribed to shadowing, also moves over the three-dimensional space of the curved piece of plaster. This unusual soft edged zone of darkness traveling in unpredictable ways through the image volume lends a sense of mystery. Dawson achieved this effect by applying the holo-diagram, a graphic invention by Nils Abramson for plotting physical zones of the repetition of laser coherence and incoherence (lightness and darkness) (Abramson, 1981). Abramson's application of the holo-diagram enabled him to avoid the dark zones and thereby record a large piece of machinery all in light with a short coherence laser whereas Dawson intentionally located the zones of darkness in a different way.

In order for the interference pattern to be recorded as a hologram, all elements involved in the recording process including the optics and the subject must remain absolutely static throughout the duration of the exposure time. Unless a pulsed laser is used, a living hand cannot be static to the required extent. Benyon's effect was achieved by intensionally using the long exposute of a continuous wave laser to allow the stable inanimate objects to be successfully recorded as bright light forms and the living hand to not be recorded and therefore become dark. Darkness of a holographic subject is generally regarded as a mistake. Saxby's fault- finding chart proposes that the only way to get around the problem is to "use a more rigid subject" (Saxby, 1991). As Benyon points out in discovering means for manipulating this representational system:

The physicist tries to get an approximation close to reality, to eliminate properties of the medium that distort, whereas it could be exactly those properties that make it unique to the artist (Benyon, 1994).
