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Throughout the
reviews pages of this site, you will notice that we include Lux
(technically: lumens/meter²) output for the light. Please bear with
me through this explanation. It is fairly important that you
understand what this means before you base your buying decisions on
this one measurement.
Also, let me
mention that some manufacturers use "Candlepower" or "Foot-candles"
to measure the output of their lights. Those measurements are
subject to the same problems I mention below for Lux.
There are
some quirks with the LUX
data that you
should be aware of. The reading for Lux
is taken only
at the very center of the beam. This means that you could
potentially have a light with 1 tiny LED that has all of its light
focused to a laser-like beam that may read higher than a 5 watt
incandescent that has a broad flood-like beam. The incandescent
obviously puts out more light overall, but the LED can send its
light out farther ("throw") since it is so tightly focused and as
a result has a higher Lux reading.
What Lux
really tells
is the "throw" of the light, or how good it is at projecting light
over a distance, NOT overall brightness or quantity of light
produced.
Lux readings
are strongly affected by the reflector and lens design. When
comparing lights against one another, the Lux numbers represent
how much light is hitting the target in a narrow cylindrical area
and does not represent the amount of light surrounding that area.
For example, a 3-D Maglight has a higher Lux
than a Surefire
E2, but that is because I can focus the Maglight to a tight beam
with little or no "spill light" out to the sides. The E2, however,
puts out more light overall with a soft beam and wide, bright
flood.
Here's a
good example: Here are 2 lights, both with a 200 Lux reading:

Note how the
top light puts out more light overall, but yet has the same
reading as the narrow focused light on the bottom. This is because
the bottom light focused all of its light into a narrow, tight
beam. Which is the better light? You can't tell just based on the
Lux reading.
Likewise, we
could have the following happen:

Here we have
the top light producing a nice 200 Lux flood over the entire area
of the beam. The light below produces MORE Lux at the beam center
(210), yet produces only 45 Lux at the beam periphery. The top
flashlight produces more light overall, yet the bottom light
receives a higher Lux
reading and
will light up a target at a slighter longer distance with the
narrow, brighter, part of the beam. If I only bought the light
based on the Lux reading, I may be very disappointed.
The moral of
the story is: don't base your purchase decision on one factor such
as Lux. Be sure to look at the beamshot target included with each
review to see the spread of the light beam and the dropoff in
intensity around its edges. |