Australian Holographics
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Australian Holographics was started with the specific objective to produce high quality large format holograms. After two years of research and development the company began commercial operations in 1991.
Situated on 80 acres of rural farm land 25 miles (40 km) from Adelaide, the lab's facilities included a 5 x 6 metre vibration isolation table in a studio with air-lock loading doors, large enough to drive a car onto the main table. The main CW (continuous wave) laser was a 6W argon laser built by Coherent Scientific. The company also used a 3 joule ruby pulse laser, built in collaboration with Professor Jesper Munch of the School of Chemistry and Physics at Adelaide University.
The company mainly specialized in the production of very large white-light viewable Rainbow transmission holograms, a type of holography invented in 1968 by Dr. Stephen A. Benton of MIT. In 1992, Australian Holographics produced a 2 x 1 metre rainbow transmission hologram of a Mitsubishi Station Wagon car, which was shown at Holographics International '92 conference in London.
[edit] Creating a Large Format Studio
The AH project necessitated building a large climate controlled studio incorporating a 6 x 5 metre optical table weighing around 25 tons. The system had to allow for both the creation of large-depth scenes for mastering, in addition to affording the space required for the effective production of ultra-large format rainbow transmission and reflection hologram copies. A heavy sand-filled cavity steel construction was used for the table. The suspension system was constructed around nine Firestone air bags connected to a standard pneumatic set-up with needle-valves, ballast tank and compressor. Overhead towers were designed to carry large transfer mirrors at heights of over three metres above the table. These towers were constructed from hollow steel tubes filled with sand. Over the years, lifting systems for the large glass filmholders evolved from hand operated, to mechanical and finally to pneumatic.
[edit] Imaging Techniques in Large Format Continuous Wave Holography
The requirement for stability in the CW (continuous wave) mastering process, has a surprisingly beneficial aspect, in that it allows for the utilization of unstable curtained areas to effectively render invisible unwanted elements in the field of vision. This trick is still unique to CW and is sorely missed during Pulse Holography mastering, where the problem is that often too many things are visible and there are limited methods available to conceal them. Thus if a large object is required to apparently float unsupported in space, CW mastering, rather than Pulsed, provides the means to easily achieve this illusion. Many important elements involved in producing high quality large format holograms rest not so much with the traditional concerns of holography but rather with aesthetic concerns that relate to table layout, and lighting techniques that endeavour to feature the subject without visual distractions and to control glare and reflections that lead to non-linear noise.
The specifications of the vertical film alignment in the holographic camera
During the holographic mastering process for large format Rainbow Transmission Holograms the strip of holographic film that becomes the H1 hologram master must be positioned in front of the subject (3D model) in such a way that it is bathed in diffused laser light, but importantly, must be held rigidly and firmly flat against a sheet of glass. Typically, elaborate hydraulic or vacuum systems have been employed to compress holographic film during the exposure process. However this function was achieved at Australian Holographics by the construction of what was referred to as 'the camera'. In fact the camera was a very long and narrow glass box, approximately 2.2 metres long, about 12 cm high and about 6 cm deep. Inside this 'camera' was a loose piece of glass slightly shorter than the length of the camera, but around the same height.
The surprising utility of: Johnson's Baby Oil ®
The long strip of holographic film was placed between the loose glass sheet and the front of the camera, and the entire camera box was then almost filled with Johnson's Baby Oil. This unusual element to the high tech array of equipment and processes came about after the exhaustive testing of the refractive index of countless varieties of commercially available oils, and to the surprise of the holographers concerned, none could surpass the efficacy of this product. The function of the oil inside the camera was to act as an agent to cause the camera to flatten the film between the two glass surfaces. As the oil slowly seeped out between the film's surface and the two glass sheets the natural viscosity of the oil maintained an ultra-thin but cohesive layer that had the effect of gradually pulling the two glass sheets together with a level of force sufficient to flatten the film to within the tolerance level that allowed a consistent interference pattern to be recorded on the H1 master.
[edit] History
Australian Holographics Pty Ltd. was incorporated in Adelaide, South Australia in 1989 by Dr. David Brotherton Ratcliffe. Dr. Ratcliffe was at the time a Research Fellow in Physics in the School of Physical Sciences, at Flinders University. The senior holographers working with Dr. Ratcliffe were initially Mr. Geoffrey Fox, and subsequently Mark Trinne.
In 1992, David Ratcliffe formed GEOLA Labs in Vilnius, Lithuania to concentrate on the manufacture of pulsed Neodymium YLF lasers. In May 1992, Mr. Simon Edhouse joined Australian Holographics as Marketing Manager, becoming General Manager later that year. The company then focused its attention on the international science museum community, selling large holograms to museums in Hong Kong, Singapore, Taipei and Japan. In 1993, Australian Holographics was commissioned by the Sunkung Corporation of South Korea to produce an exhibition of ten large format holograms for Expo '93.
In October 1993, David Ratcliffe relocated to Europe, and handed operational control of the day-to-day running of the Adelaide studios to Simon Edhouse, who continued to manage the business as Managing Director of the newly incorporated vehicle of Multi Cellular Media Pty. Ltd. trading as 'Australian Holographics'. The company formally known as Australian Holographics Pty. Ltd. changed its name to A.H. Studios Pty. Ltd. which was effectively managed until 1998, by Ms. Svetlana Karagonova.
In 1994, Australian Holographics produced a series of holographic billboards for the Singaporean military to promote the 'NS Men' (National Service Men) campaign. The holograms were of the rainbow transmission variety, enclosed in a compact viewing enclosure which housed a mirror to extend the light path for optimal viewing conditions. Also in 1994, Multi Cellular Media Pty. Ltd. trading as Australian Holographics, signed a joint venture agreement with the South Australian Museum, giving the company access to the Museum's vast collection of exhibits.
A Holographic Diorama of Extinct Thylacines
One of the first projects undertaken by the new venture was the production of a 1.6 x 1.1 metre rainbow transmission hologram of a family of thylacines. The holographic thylacines, shown standing on a rocky outcrop in a field of dry grass, portrays the now extinct Thylacines as a family group, with the small thylacine pup protruding 50 cm in front of the holographic image-plane.
The company also produced a 1.5 x 1.1 metre hologram of a Tyrannosaurus Rex skull from the S.A. Museum's collection.
In 1995, a large series of holograms were produced of satellites and space vehicles. The most notable of these holograms was the giant 2.1 x 1.1 metre rainbow transmission hologram of the MIR Space Station. This hologram showed a 2 x 3 metre scale model of MIR apparently floating high above the Earth. The model of the Earth used in this hologram was custom made by Adelaide Artist John Haratsis. It measured 4 x 5 x .6 metres resembling a thin slice of a much larger sphere.
In 1996, a 'Great White Shark' hologram was produced by the company from a 4.5 metre model made in Queensland by David Joffe. The resulting 1.5 x 1.1 metre rainbow transmission hologram would become the most popular of all the Australian Holographics stock images, being sold around the world to museums, private collections and tourist venues.
