Creating a Lighting System for a House of Worship - Part 2
May 06, 2009
Layers of Light
In Part 1, we had begun to review the basic elements required to create a flexible lighting system that is supportive of a space but that also takes into account the fundamentals of the liturgical actions and other events that may occur within a space. Our next step is to review the basic elements in a space referred to as “layers of light.” These tiers of light (1) assist the viewer in perceiving the depth of the space; (2) objectify areas of significance; (3) create a ratio of light-to-dark and light contrasts; (4) create visual observations regarding the perception of a space; (5) set a tone and mood; and (6) extend lamp life and conserve energy.
As an example, imagine being in a church with a high center nave and shorter side aisles. Try to visualize that you are turning on some lights to illuminate the side ceilings; however, there is no illumination in the nave. To the viewer, the space would appear shallow and wide. Now, let’s turn those lights off and illuminate the ceiling of the high center nave and blot out the lights on the side aisles. The feeling now is that the space is high and narrow. This simple test illustrates that our consciousness of the space is perceived through our vision and experience suggests that the light should be in balance and follow a natural course. It is from this basic starting point that one begins to create a lighting system for a house of worship.
Lighting designers use many different approaches; however, perhaps the most important issue is the matter of foot candles, or more specially, the contrasts by which the human eye perceives levels of light and how that perception changes from area-to-area and object-to-object. Within this lighting paradigm, one must consider the foot candles for reading and the vertical foot candles when lighting for emphasis. The human eye can detect contrasts when the lighting level is greater than three to one; thus, accent lighting should be three times the level proscribed for reading. In order to eliminate distracting pools of light, the specified lighting should be visually smooth and not too high nor too low so it detracts rather than supports the areas of concern.
Channeling the Light
Once you have established the concept of layering the lighting, the next step is to group the lighting into channels to provide the illumination needed to support diverse events, e.g., daily Mass, a wedding, a talk, etc. This channeling develops scenes as a filmmaker would. Various levels of light are selected to create a specific visual environment or mood. For example, in the celebration of a daily Mass, only the forward portion of the nave might need to be illuminated with lower levels of light in the back. The altar and ambo would be illuminated so that when the presiding minister moves into the pools of light, the eye would be drawn to the higher levels of illumination. Channeling permits the management of a lighting system within the total space down to the most intimate, quiet occasions within the church space.
Quartz Tungsten Halogen Lamps
The most appropriate lamp for important lighting applications that are color sensitive and require consistent dimming possibilities are the frosted, quartz tungsten halogen lamps. Their makeup involves the quartz that is the outer envelope of the system: The tungsten is the material that is used to make the filament and the halogen gas that is contained within the envelope. The reason for the use of the tungsten filament is that when the filament has been energized, it flakes off a portion of its mass as a result of the energy passing through. When the lamp is in full power, the halogen gas in the lamp envelope reattaches the flaked-off halogen onto the filament and this action allows a more consistent performance until the end of its life.
The issue of constancy of performance and long life is important because many other lamp sources cannot duplicate their action and have a short-term durability. In addition, by running the quartz system through a dimmer, the lamp life Is extended by approximately 20-25%. Another fact to consider is that when fixtures are not utilized to their full capacity, the savings is reversed because the fixtures are not permitted to move through their full cycle.
The dimming system was introduced in Part 1 of this article series. Adding a dimmer to the electrical system permits the prearrangement of setting scenes for services and special occasions within the sacred space. A scene is created when particular zones of light are predetermined and then arranged and controlled by a dimmer. For instance, in a setting for a pre-and-post liturgical celebration, the altar may be zoned at 60% illumination; whereas, the choir might be at only 30%. Or, the downlights within the space may be set at 30% illumination, while the uplights in the front of the church could be set at 60%. Typically, dimming systems have 4, 8, 12 or 16 preset scenes and one manual scene. The manual scene gives the system the flexibility it needs so that the automatic presets do not have to undergo changes. Strongly recommended are:
» Control boxes that can be locked so that “improvements” are not undertaken by staff who are unaccustomed to the presets in the system; and
» At least one scene should run the system at full power so that the halogen cycle can be reactivated.
In Part 3 of this series, ideas will be offered that will assist in developing ideas for lighting houses of worship and in seeking professional assistance with lighting needs.
Edwin P. Rambusch is a project manager at Rambusch Company, New York City, New York, with an emphasis in custom and restoration projects.
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