Maintaining good color recognition from high-pressure sodium lamps, Bullough says, can be achieved by using at least 3 footcandles
The first thing to determine is the number of horizontal footcandles
(lumens per square foot) required on the pavement for various conditions.
Minimum Light Levels for Common Potted Plants in Interior Landscape Settings 50-100 Footcandles
Azaleas Anthuriums Calceolarias Chrysanthemums Bromeliads Cinerarias Kalanchoes Cyclamens Easter lilies Poinsettias Jerusalem cherry Gloxinias Orchids Hibiscus Ornamental peppers Hybrid lilies Rieger begonias Hydrangeas Spring bulbs Source: Dr.
Note that recommended light levels are always for average maintained footcandles
. Initial footcandle
levels - when a system is first installed - may be as much as ten percent higher than maintained, but will drop off over time.
. Basic to the process of measuring footcandles
is the availability and use of the proper measuring device.
A parking lot generally requires O.S footcandles
for security, and you can achieve that a lot more easily with today's optics and not waste any light.
With that, "darkness was pivotal for creating a sense of drama and mystery, so the lighting level for the gallery is deliberately kept low at 5 footcandles
. The low light levels cause minimal light spill and do not interfere with the display lighting."
Traditionally, designers have focused on the required footcandles
needed for a space; however, the lightness of the walls, ceiling, and partitions also affects the perceived brightness of a space.
Tretter specified 2.0 footcandles
, requiring four poles in the main yard, each holding four Venture 400-watt pulse start lamps.
or pavement) Footcandles
High 10 0.9 Medium 6 0.6 Low 2 0.2 Covered Parking Day Lux on pavement Footcandles
General Parking 54 5 Ramps and Corners 110 10 Entrances/Stairways 540 50 Night General Parking 54 5 Ramps and Corners 54 5 Entrances/Stairways 54 5 Reprinted from the IESNA Lighting Handbook, 8th Edition.
California Assembly Bill 244 set technical standards for lighting at the machine's face (10 footcandles
), up to 50 feet away from the machine (2 footcandles
), and in the nearest parking area designated for ATM users (2 footcandles
You can have enough light inside with 30 to 50 footcandles
, and there's 10,000 footcandles
on a bright sunny day.