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Vital Signs Project: Monterey Bay Aquarium Visual Comfort Study

 


Conclusions

A trio of Monterey Bay Aquarium visitors in one of the darker spaces near the Kelp Forest.

The Monterey Bay Aquarium is perhaps the most complete and spectacular aquatic museums in the United States. Overall, the aquarium is very successful in exhibiting sea life in a comfortable and interesting fashion. The lighting designers and architects must be commended for their skills in successfully developing a space where light levels can fall well below 1 (one) footcandle while strategically providing sufficient light for reading exhibit panels. Upon a careful investigation, however, I discovered some minor problems with respect to light quality and visual comfort. The less dark spots in the corridor are slightly underlit. This might explain that fact that during my visit, I noticed that visitors did not always stay focused on the exhibits. When people move from the generally darker areas of the building to the brighter daylit portions, the transitions from dark to light becomes a source of visual discomfort. The human optical system requires several minutes to fully and comfortably adjust to significant changes in light levels. Unfortunately, the dimensional layout of the exhibits and the lighting system within the Monterey Bay Aquarium does not allow for this comfortable transition. This short time for transition, however, does not create an unsafe situation.

Along the paths of the aquarium, the exhibit luminances are fairly consistent at 1 cd/m2 (candelas per meter squared). Luminance readings from the exhibit signs range from 5-10 cd/m2, while the dark areas are about 0.1-0.2 cd/m2. While focussing on the exhibits, visitors experience a 1:10 luminance ratio in the dark corridors. According to Fuller Moore, this is a comfortable ratio that focusses attention on the exhibits. During my visit, I did not feel that this difference in luminance was particularly disturbing. The larger, brighter exhibits and signs in the Kelp Forest have luminances of over 10 cd/m2- comfortable compared to the 100+ cd/m2 of the lobby walls and signs. There are a few areas, however, where luminance values exceed Moore's suggested maximum comfort ratio of 40:1. These areas often provide some sense of visual discomfort.

Room for Improvement

In all of the Monterey Bay aquarium, these are the three areas which could use some lighting improvements:

1. The greatest visual discomfort occurs as one returns to the lobby from the Octopus area. This discomfort is caused by the fact that one confronts a large window looking onto a bright background immediately after being in a relatively dark exhibit area. These exhibits are the first one encounters upon entering the aquarium, however, on the way into the aquarium, they can be visually avoided as they remain along the side of one's cone of vision.



2. Visual discomfort also occurs near the area from the Shale Reefs to the Slough. This area was observed to be a very common path through the aquarium. Though the Wharf area helps the eye adapt to a more luminous environment, the large window at the north end of the Slough is very bright and visually dominating. If one examines the exhibits on the side wall, uncomfortable glare can be attenuated.



3. The final source of significant visual discomfort occurs on a path from the Bay Model area to the Rocky Shore, as the corridor ends in a large window. All of these windows have a layer of tinted film, but are still too bright for someone emerging from the darker corridors.

Closing Thoughts

Lighting standards have evolved over the years as technologies have enabled greater variety in light installations. Workspace illuminance standards have grown from 3 footcandles near the beginning of the century to 100 footcandles in the sixties and seventies. And today, they vary widely according to application and energy efficiency goals. Such standards are designed partly to maintain public safety and visual comfort. This study shows that, overall, the Monterey Bay Aquarium is exemplary in its creative ways to allow for very low light levels without sacrificing safety and comfort.

As the Monterey Bay Aquarium finishes its new wing, doubling exhibit space, the building designers face similar challenges of providing low light levels while maintaining public safety and visual comfort. The Aquarium continues to experiment with new methods as it prepares the world's largest single exhibit, a million gallon tank behind a 55' x 16' acrylic window, situated in a dark auditorium-like room. This room does not use the aisle spotlights found in the rest of the aquarium, but dim-blue fixtures instead. It will be exciting to see what new methods the Aquarium will use to make the dark so enlightening. Vital Signs encourages readers of this case study to visit the Monterey Bay Aquarium and report your personal findings.

Comments to author: vitalsigns@
ced.berkeley.edu

All contents copyright (C) 1998. Vital Signs Project. All rights reserved.

Created: 07/01/96
Revised: 09/09/02

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