Phantascope Phantascope
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A combined pocket size Hyperscope & Psudoscope,
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Further Experiments - Texture Screens

So far the contrast between the model or figure and its ground has been high in order to make it as easy as possible to see something hard to see. The models have operated in visual contexts, which have emphasised the contrast between figure and ground. This is important initially to establish familiarity with some of the unusual characteristics of pseudoscopic perception.

Barbara Gillam, Professor of Psychology, University of New South Wales, suggested that visual contexts for these demonstrations, which eliminated the contrast between figure and ground, be considered, and as a result I have developed a series of 35mm texture screen transparencies for projection. The model to be used for this demonstration need be no more complex than a cylinder of white cartridge paper 3ft (1.90m) long and about 10" (25cm) diameter, and suspended centrally, so that it will hang horizontally from the motor drive cord.

Darkened viewing conditions will be most effective, but semi-dark conditions when the patterns are still visible are quite acceptable.

Seen through the Pseudoscope the model will produce the following effects:

  1. The model itself will become an impossible transforming hole in the wall,
  2. The convex cylinder will become concave,
  3. The shadow will appear to be in front of the model,
  4. The shadow will appear more solid than the model,
  5. The source of the light falling on the cylinder appears indeterminate.

Use of the Pseudoscope on Natural Scenes

Although the cues to pseudoscopic vision work very strongly against normal vision, the enhancement of the pseudoscope is such that it can be directed very usefully at normal scenes. Nevertheless, it will be better if the scenes include some ingredients which can more easily become pseudoscopic such as glass, water, or potentially ambiguous structures. Large trees,particularly if they are wind blown, become crazy, weird, impossible sights,and make even the most exciting holograms obsolete.

Siting the Rhombus for Demonstrations

The rhombus should be suspended about 2ft (60cm) in front of a plain white wall, and about l2ft (4m) away from the Pseudoscope. A dark wall works perfectly well for the rhombus, but to make use of the behaviour of shadows and the projection of texture screens, a white background doubles as a screen. For the purpose of didactic demonstrations, adjust the amount of turn in the pan-head so that, if possible, the field of view includes only the rhombus and its background. Pseudoscopic vision is so unusual, that if this is not done, some observers may think at first that there is something wrong with their eyes. IT IS IMPORTANT TO SET UP A DEMONSTRATION WHICH ENSURES THAT OBSERVERS SEE WHAT THEY ARE MEANT TO SEE.

Therefore, if it is possible, site the Pseudoscope so that it may be directed at the rhombus with the pan-head set for limited or no radius of turn at all, but when full radius of turn is restored, it could, in addition, view scenery such as described above.