Moonlight & LED CCT analysis from Benya Burnett Consultancy, Davis CA.
“After the city staff
reviewed available options, it
was determined that the
4,000K CCT color
temperature and the
perceived increased
brightness of fixtures were
the primary causes of the
negative public reaction.
Several remedial actions
were considered, but
ultimately in October 2014,
the decision was made to
replace 650 of the already
installed fixtures in
residential areas and all
remaining LED fixtures with
Leotek 19-watt Green Cobra
Jr., producing approximately
1800 lumen at 2700 Kelvin
(soft-white).
In addition, the installation
would increase the number of
house-side shields to reduce
glare and light trespass”
Davis, California article here
by Volt.org - more LED
RetroFit Streetlights.
LED Streetlight
Retrofit…
This spectrum analysis shows the comparison of the natural moonlight and
LED at 4000 Kelvin. The blue spike makes LED unique and problematic. Blue
is daytime for your body and health issues are now being connected to blue
lighting from LED streetlights, cell phones, computers, and televisions.
Apps can be used to ‘filter blue’ out at nighttime on your cell phone(s).
GLARE and REFLECTION of bright outdoor lighting are unintended
consequences which start in brochures and end up hurting our outdoor,
nighttime, environment.
High Kelvin numbers - above 3000K, create a light source that is like
daylight for people and wildlife. These make it hard to see into the nighttime
and when one all night are ‘blinding’.
Blue spike can be reduced with 2700-3000K LED streetlight models. These
‘soft-white’ 2700 Kelvin LED fixtures often reduce glare and allow better
night vision for pedestrians and bicycles.
Soft-white LED can be found for your home too and are often 2700 Kelvin.
Many cities are now picking streetlights below 3000K. Soft-white and
dimmer LED models allow good vision at night while providing even
better energy savings.
Click here to
see City of
Phoenix LED
street and park
lighting rated
at 2700 Kelvin.
Edison light bulb was
developed after many tests.
The incandescent bulbs are
at about 2600 Kelvin and
the meter shows the visible
spectrum that works very
well in our eyes.
Comparison of three LED (light
emitting diode) light fixtures.
Click on these to enlarge each one.
Department of Energy 2013 Research on
pedestrian lighting needs and better LED lighting
approaches - here.
Understanding Quality of Light!
International Dark Sky Association with three
decades of experience, great resources, and
experts that help with accurate evaluations. Our
friends in Tucson were a GREAT help to
Phoenicians in leading the world to better 2700K
LED street and park lighting! More here.
Options for LED for your home…
We can all benefit from LED lighting. In our homes,
‘soft-white’ bulbs are typically rated at 2700 Kelvin.
Check on back of case before you buy new lighting for
your home or business. See Cree LED example below -
right. Good news includes more energy efficient and
LED are not very hot. Special dimmers are necessary
but they save more energy then old ‘watt’ dimmers.
EXCELLENT outline of TERMS & TIPS from
experts on LED lighting and the evolving
technology; click here for pdf with more links.
Cree LED 2700K is a ‘soft-white’
light bulb for your home. The
visible spectrum here is similar
to the Cree street lights used in
Phoenix.
June 2016
AMA - BLUE LIGHT
SERIOUS HEALTH CONCERNS
AMA Compete Guidance to reduce
health issues from high intensity
lighting - here.
BLUE SPIKE from some LED
streetlights, cell phones, computers,
and TV’s, can negatively affect your
health according to American Medical
Association. AMA Press Release - LED
Health Concerns - Light Pollution
problems here.
AZ Doctor raised new LED streetlights
& health issues with City of Phoenix on
TV Channels 3 and 5. Read problem
and solution here.