Laserfiche WebLink
<br />Information Sheet 139 (July 1998) Page 3 of 4 <br /> <br />Light output from a fixture should be limited to more than IS degrees below the <br />horizontal plane. Any attempt to floodlight objects at a distance of more than 4 <br />times the height of the light fixture creates glare and light trespass, and decreases <br />visibility and safety. <br /> <br />There needs to be a footcandle limit (such as 50 fc for convenience store/gas <br />station canopies) to stop this ratcheting war and help improve visibility at night. <br />Why should 85 fc be needed outdoors when less than 50 fc are required indoors? <br /> <br />Billboards and signs should be lit from the top down. The practice of lighting <br />billboards from the bottom up seems to be more for the convenience of the service <br />company than anyone else. Even a casual inspection of bottom-lit billboards <br />reveals that the majority of the light is escaping into the sky. Billboard lighting <br />can be accomplished from the top down, and with far less light by using fixtures <br />that accurately direct the light at the sign face. <br /> <br />A good outdoor lighting code or ordinance could help a community save <br />substantially (50% or more) on energy use and dollars spent to operate outdoor <br />lighting. Cities like Tucson, Arizona have already demonstrated how it can be <br />done. The reasons behind the regulation of outdoor lighting should be clearly <br />stated in such ordinances. For example: <br /> <br />· The improvement of safety by eliminating glare and providing for a more <br />even illumination <br />. Saving energy by not wasting light; using light only where and when it is <br />needed <br /> <br />Light levels should be downsized to no more than the IES (Illuminating <br />Engineering Society) recommended levels. <br /> <br />In March of 1997, from downtown Tucson, I observed Comet Hale-Bopp with a <br />20 degree tail magically suspended over the palm trees. I remember wishing that I <br />could share this experience with every city mayor and council member. The need <br />for a safer environment, energy savings, and improved aesthetics -- while all <br />desirable -- seemed to pale before the magic of this wondrous celestial visitor, <br />Comet Hale-Bopp. With considered thought and planning, any city could offer its <br />citizens such sights, and the many other advantages of good outdoor lighting. <br /> <br />John Gilkison <br /> <br />http://www.darksky.org/infoshts/isI39.htmI <br /> <br />6/20/2005 <br />