The size of the light source for Sox and Son lamps determined the size of the optical control and lantern. This limitation of control produced the familiar orange sky glow around all urban centres. The change to LED provided an opportunity for the professional lighting community to change the approach to delivering light where it’s needed. The previous HID lamps ( Sox & Son) wasted at least 30% of the light from the lamp in an uncontrolled way into the atmosphere and refracting in the dark sky with dust and water particles (and/or molecules) to produce that familiar orange aura.
OrangeTek’s consistent approach for delivering the light exactly where required, was an overlay approach. Each LED chip has its own lens, and that lens produces a footprint on the ground. Each lens duplicates that footprint, and so like a layer cake the light levels are built at top of each other. There is no wasted light with LEDs, as all that light is focused through the lens to light the desired area. The lens design allows some forward and back light to help illuminate the immediate surround to the highway for feeling of comfort and security.
All our lanterns produce ZERO upward light, so that’s Nil light at or above 90degrees. That is why these are approved by the IDA and can produce dramatic changes in the environment, as can be seen in Dumfries and Galloway below.
At first LED chips were most efficient at 5000- 6500K and around 100lumen per watt (lm/W) and tended to have a high blue light content at these colour corrected temperatures (CCT), and as blue light tends to scatter in air more easily then the red end of the spectrum, it proved more difficult for astronomers to view the heavens at night, even though the new LED street lights provided the best ever light control. Recently LED chips have improved substantially and at much warmer white at 3000K with a much-reduced blue element they are around 180lm/W. We are constantly seeking options to improve this further and can now provide luminaires with a similar CCT to that of a tungsten lamp and in addition provide specialist Amber Chips to be used near Observatories or key wildlife installations.
The International Dark-Sky Association (IDA) is the recognized authority on light pollution and is the leading organization combating light pollution worldwide
The Fixture Seal of Approval program was introduced to provide objective, third-party certification for lighting that minimizes glare, reduces light trespass and doesn’t pollute the night sky.
The three main criteria must be met to become approved.
Find out more at www.darksky.org/