There are three promoted figures
related to brightness of LED fixtures; LED power, Lux, and Lumen, and these are
all related in some way but many LED lighting manufacturers mis-communicate the
advantages of each.
LED Power
A high wattage LED power doesn’t
necessarily mean a high brightness. It depends on the quality of the LEDs and
the Lumen efficacy. A common assumption is that a 3W LED is brighter than a 1W
LED, but this is often not the case as it depends on the quality of the LED,
the beam angle, and the color range. Astera has very high power LED spotlights
(up to 135W), but also manages to retain high brightness with its use of
Philips and Cree LEDs.
Lux
Lux is the unit of measurement
for luminous emittance (light emitted from a surface) and breaks down as the
amount of Lumen per meter squared emitted from that surface. Many manufacturers
quote a high Lux figure but they do not mention two important pieces of information;
- The distance of the light from the subject
- The beam angle of the LED light source.
As a consumer, these are needed
in order to prove the brightness (and if these are not present, the
manufacturer is probably trying to hide something).
In order to get an accurate Lux
reading, an area of 1m² needs to have light shone onto it. For example; a light
source with a 15 degree beam angle needs to be placed 4.3m away, and a light
source with a 30 degree beam angle needs to be placed 2.1 meters away, for them
to both cover an area of 1m². Pay attention to this when comparing Lux values
as there are many tricks that manufacturers play.
Lumen
Lumen is the measurement of light
and its sensitivity to the human eye. The Lumen scale describes the amount of
light, or brightness, that the human eye perceives from a light source. Apart
from straight-up lying, there is not much that manufacturers can mis-communicate
here. It is measured using a light sphere and spectrometer. When a color
is not stated, assume it is 6000K Cold White. Every manufacturer will use this
as it gives them the best chance of getting a higher lumen value.
Click on the box below to:
No comments:
Post a Comment