Lighting : Lighting October 2014 - Vol 34 Issue 5
October/November 2014 | LIGHTING MAGAZINE 39 38 LIGHTING MAGAZINE | October/November 2014 various wattage metal halides and determined the optimal illumination and settings for lighting to control shark behaviour and their operational depth. OTHER HABITATS The forty smaller habitats were more intimate but equally complex affairs. Here artificial lighting invited crabs out to feed, octopus to move and little fish to emerge. Figure 3 shows the Indian Ocean foreshore habitat in winter twilight mode. Imitation of cave and variable light was achieved from 27 and 53W asymmetric and symmetric LED and 20W metal halide with spreader lens. Blue LED backlight was used to highlight the rockery. The light switching required four separate circuits to provide day/night transition. The touch tanks and walk over habitats were interesting. The former encouraged visitors to handle marine life and to do that the design provided 150W narrow beam metal halide lights overhead and LED wall-washers to illuminate surrounding instructional posters. The walk over habitat gave visitors a close and personal view of marine life. Here safety and maintenance issues were paramount. The design used IP68 low-voltage LED linear lights under gravel or recessed into rocks. MARINE CORAL AND PLANTS The lighting design catered for the health and survival of marine coral and plants, including mangroves. Most coral, for example, draw their energy from the sun through photosynthesis. Coral converts light energy into chemical energy. Inadequate and incomplete light kills light- dependent coral and therefore fish habitat. Consequently, certain colours and wavelengths and timing and intensity of light are essential for healthy coral, sponges and marine plants. So, colour temperatures ranged from 3,200K to 10,000K and CRIs ≥ 90 were achieved. Later, due to commercial constraints, predation and numbers of fish, greater use was made of artificial coral and flora/fauna. It is hard to tell the difference between artificial and living marine coral and plants (Figure 4). THE UNDERWATER TUNNEL The acrylic tunnel, allowing visitors to view the larger habitats, was not lit (Figure 5). Lighting positions and illumination calculations ensured enough indirect light to allow safe passage and meet safety codes. The design also created backlit drama and drew visitors’ eyes to movement beyond the acrylic walls. The Park includes amazing hotel suites and a restaurant with stunning views of the main habitats. Here the focus was on reducing glare and creating dramatic visual experiences. The location and intensity of lighting for habitats could not inhibit the spectacle from these human spaces. We calculated horizontal and vertical illuminances, eliminated direct sight of luminaires, suspended and hid luminaires and paid special attention to the cut-off angles. FINALLY Lighting, habitat research, mathematical models, luminaire selection and specifications and final design took two years. All decisions were continuously balanced against marine life needs and budget, public benefit, project and energy constraints. Most of the detail of the work remains our intellectual property. We hope that we have shared enough to appreciate the complexity of lighting an underwater world. Moreover, in creating this lighting solution we contributed to the life support system sustaining many beautiful sea creatures as well as the bottom line of our client. Figure 3. Indian Ocean winter twilight foreshore habitat. Figure 4. The lighting catered for living marine coral and plants. Figure 5. The underwater tunnel.
Lighting December 2014 - Vol 34 Issue 6
Lighting August 2014 - Vol34 Issue 4