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201 Daktronics Dr. PO Box 5128 Brookings, SD 57006-5128 tel 800-325-7446 605-692-0200 fax 605-692-0381 www.daktronics.com DF -02 7 6 6 May 9, 2016 City of Arden Hills Re: Lighting Analysis for Daktronics LED DVXMC Scoreboard To Whom This May Concern: The accompanying graph pertains to the Daktronics LED DVXMC scoreboard proposed for installation at Mounds View High School located at 1900 Lake Valentine Rd. in Arden Hills. Additionally, answers to requested information from the City (letter dated April 21, 2016) is documented in Appendix A. We hope you find the following information beneficial. Daktronics’ lighting analysis are computed using a measurement of illuminance (footcandles) in order to show a display’s light impact at various angles and distances. The unit ‘Nits’, a measurement of luminance, measures the amount of light a sign emits and is used by manufacturers to specify maximum daytime brightness of an LED display. While Nits values do change at various angles from the display face, measuring in Nits does not correlate to how much light output will reach certain areas. For instance, as the measurer stands at off angles, the physical size of the display that is viewable decreases significantly, however, measuring in Nits would not account for this decrease in viewable area, and thus provide an incorrect measurable to the light impact. On the other hand, footcandles measures the amount of light that hits a certain location, such as 450 ft from the face, a neighboring roadway or house. Since the lighting analysis was completed to address light impact to the adjacent roadway and neighboring residential areas, footcandles would be the recommended form of measurement. The accompanying graph depicts illumination levels in footcandles that the proposed display will produce based on nighttime running levelsi at a measurement height of five feet above ground level (which is approximately eye height). ii These levels are based on a worst-case scenario of an all-white display. Actual levels will be much lower than what is represented on the graph, as typical content runs at 25 to 35 percent of the brightness of an all-white display. It is important to note that the accompanying graph assumes absolute darkness with regard to surrounding ambient light. In other words, the presence of ambient light producing elements at night including but not limited to roadway lighting, residential lighting, the moon, etc. will further diminish the impact of the light output from the display in question. If there is a game at night utilizing the scoreboard, the presence of spotlights to light up the field will significantly reduce any display lighting impact. It is also important to note that the accompanying lighting analysis graph shows there will be no lighting impact from the Daktronics LED scoreboard to Lake Valentine Road and the residential neighborhoods to the north and east of the stadium. For example, at 450 ft and an angle of 75 degrees, the graph shows a lighting level of 0.00 footcandles.