Crescent Heights Light Pollution and Responsible Lighting Field Trip
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Crescent Heights Light Pollution and Responsible Lighting Field Trip Print this guidebook to take with you and experience the pleasures and woes of good and bad lighting in one Calgary neighbourhood for yourself. A version of this guidebook designed for personal digital assistants (PDAs) will be available shortly. This guidebook is also available as a virtual tour on the Light Pollution Abatement pages of the Royal Astronomical Society of Canada, Calgary Centre, website, www.syz.com/rasc/lp/. Map of Calgary showing location of Crescent Heights (from the City of Calgary Planning Department). The Crescent Heights district is typical of inner city settings in Calgary. Residential areas consisting of a mix of older homes, newer infill houses and small condominiums are adjacent to a wide range of commercial interests, including automobile sales, service and fueling, furniture sales and professional services. This is all thoroughly mixed with a number of eclectic restaurants and neighbourhood bars to ensure a vibrant evening pedestrian environment. Crescent Heights is also host to three of the main traffic arteries in Calgary. Centre Street and Edmonton Trail are two of only four Bow River crossings in the downtown region. The Centre Street Bridge with its lions and other features is a key architectural icon in our city (albeit a glary one at night). This bridge ensures a high traffic volume on Centre Street on top of the local business-generated visits. The other main street is 16th Avenue North, also known as the TransCanada Highway. Both 16th Avenue and Centre Street have a high commercial content; Edmonton Trail is commercially developed only intermittently. It is precisely this evening environment with its pedestrian and high automobile traffic levels that makes having responsible lighting important: compromising visibility with glary lamps, or widely varying levels of illumination, is a sure way to obscure pedestrians from drivers’ sight or to create areas with the potential to hide hazards. The interface between commercial and residential properties is another area where the improper use of outdoor lighting can cause friction. In the Land use Bylaw 2P80, sections 33 (13) and 42.1 (6) state, All on-site lighting shall be located, oriented and shielded so as not to adversely affect (the) adjacent residential properties. In our opinion, there are a number of businesses in Crescent Heights that do not comply with this bylaw. A word about the photographs: It is impossible to render nighttime scenes exactly as the eye perceives them. The eye’s ability to view differences in brightness is not the same as that of film or a digital camera. In some instances, film or digital media are superior to the eye: cameras can be set to overrule the brightness information of a scene to bring out details in the shadows or in the highlights. The eye always responds to scenes’ brightness through a combination of sensitivity changes of the rods and cones (dark adaptation) and changes in the diameter of the iris. Crescent Heights with the location of the Light Pollution Field Trip indicated. Map modified from a City of Calgary Planning Department document. Trip Log From the parking lot at 1st Street N.W. and 14th Avenue, proceed south and east on 14th Avenue N.E. to Stop 1. Stop 1. Lambda Oriental Foods has chosen responsibly for its parking lot lighting, employing low glare full cut off “shoe box” fixtures. Unfortunately, any benefits resulting from the good choice of lot lighting are negated by the glary wallpack lights. On the positive side, this establishment now apparently turns these wallpack lights off after the close of business. Walk southward one block on the west side of Centre Street , crossing 13th Avenue, turn right and proceed to the west (alleyway) side of the Shoppers Drug Mart. Stop 2. An unshielded drop lens fixture streetlight in the alleyway behind the Shopper’s Drug Mart on Centre Street causes glare. Stop 2. These full cut- off wall lamps on the side of the Shoppers Drug Mart are an example of responsible lighting. The low-glare design means that light is directed downwards where it is needed. These fixtures face the adjacent residence but do not shine towards it. Continue south in the alleyway to 12th Avenue N.W. where we’ll find Stop 3. Stop 3. Although the lamps illuminating the entrance of this Scotiabank are directed downwards, eliminating uplight, the area is overlit in our opinion. High intensity lamps like these increase the contrast between lit and unlit areas, reducing overall visibility. With eyes adjusted to the bright lighting levels on the left, it may difficult to discern details on the right, where the other person is standing. To get to the next stop, turn left on 12th Avenue, proceed to Centre Street and cross 12th Avenue, heading southwards on the west side of Centre Street. Stop 4. Four high intensity lamps mounted at a 45 degree angle illuminate the lot of this automobile dealership, causing significant glare for southbound drivers on Centre Street. On a positive note for adjacent residences, this automobile dealer has opted not to use the excessive illumination levels that some other dealerships in Calgary have. Continue southwards on Centre Street to the next stop. Stop 5. These globe light fixtures employed by Stuart Olsen at their doorway actually put more light upwards than on the ground. While normally obtrusively glary fixtures, these globe lights use a subdued level of illumination to be decorative without reducing visibility. Continue southwards on Centre Street. Stop 6. Although situated in a doorway under an awning and producing no uplight, this wallpack fixture sprays a significant amount of light sideways, causing glare. In addition, the excessive brightness makes it difficult to see details in the normally- illuminated areas on either side of the doorway. Stop 7. This Petro- Canada Certigard garage turns off its exterior lights after business hours. This saves electricity, minimizes the impact on neighbouring residential properties and allows the large windows coupled with interior energy efficient fluorescent fixtures to highlight the interior of the building allowing for surveillance of the valuables inside the building. Continuing southward on Centre Street, we come to Stop 8. Stop 8. A very good example of very bad lighting! Uplight from spotlights above the Starbucks sign illuminates the upper part of this building. The light provides neither useful illumination of the ground, nor illumination of the Starbucks logo, and merely contributes to sky glow. On the other hand, the soffit lighting provides excellent low-glare illumination of the walkway and storefront. Crossing Centre Street, we come to Stop 9. Stop 9. Another example of well-designed recessed soffit lighting. Note that the illumination levels are even along the perimeter of the building and not excessively bright. Turning north on the east side of Centre Street, we walk to Stop 10. Stop 10. Recessed soffit lighting at the Associate Chiropractic Clinic provides excellent downward- directed illumination and no uplight. However, note that areas away from the doorway appear dark because of the excessive brightness of the lamps. A lower wattage bulb would reduce the contrast between lit and unlit areas without requiring extra light fixtures. Here is a case where less is more. From here, we cross 10th Avenue N.E., turn eastward and enter the alleyway behind Centre 1110. Here we encounter Stop 11, with a number of lit and unlit doorways and alcoves. Stop 11. View looking south of unshielded dusk-to-dawn wallpack light fixture allows light to trespass across back alley onto adjacent residential property. Stop 11. Unshielded dusk to dawn wallpack light fixture allows light to trespass across back alley onto adjacent residential property. There is a person wearing a bright red jacket standing on the right side of this image. Daytime view of the dumpster. Both alcoves have a wallpack fixture, but the light in the stairwell has been burned out for over a year. Note that it is the illuminated surfaces that attracted the graffiti (on both sides of the dumpster – not shown). Stop 11. Light cast by unshielded wallpack fixture discussed above shines into residence across the laneway. At the laneway “T” intersection, turn eastward, where we will examine residential lighting between 10th and 11th Avenues. Stop 12. One the south side of the alley, an unshielded light fixture produces more glare than illumination onto parked vehicles in parking stalls behind a townhouse. The light from this fixture trespasses into a neighbour’s bedroom. Stop 13. Dusk-to-dawn ‘security’ spotlights illuminate a condominium walkway leading to a carport and fully illuminate the contents of the parked cars on the north side of the laneway. These are the same lamps from the next photo below. Glare from the overly bright lamps deepens shadows adjacent to the (overly) illuminated area, making details difficult to discern. Note that few details can be discerned on the individual in the photograph. Stop 13. Dusk-to-dawn ‘security’ spotlights illuminate a condominium walkway leading to a carport. These unshielded and improperly-aimed lamps send an obtrusive glare onto adjacent properties at night and makes it difficult to discern details in the shadows. Travelling farther east, we come to Stop 14. Stop 14. A trio of unshielded spotlights produces more glare than useful illumination onto a vehicle parked in the back alley behind a townhouse. Note the shadows cast upwards from the open window to the left of the spotlights. A significant portion of the light is going upwards and to the sides, rather than downwards where it is needed. We now turn back westward, retracing our steps back to the “T” intersection.