illuminationGear World-Class Tactical & Professional illumination Tools

FAQ / FREQUENTLY ASKED QUESTIONS
A: Light Emitting Diode, are basically like tiny light bulbs that fit into an electrical circuit, that are super efficient, with high output (now providing 1,000-5,000 Lumens per LED), and with long lasting life expectancy (up to 50,000 hours). Generally the LED are permanently installed into light, and not user replaceable.

Q: What is TINT/Color Temperature/What is "K/Kelvin"?
Q: Should I get COOL or NEUTRAL TINT LED?
A: Color Temperature is a measurement in Degrees Kelvin that indicates the hue of a specific type of light source. K/Kelvin is a unit of measure of Color Temperature - higher color temperatures (5500 K or more) are "COOL" (green–blue) colors, and lower color temperatures (2700–3000 K) "WARM" (yellow–red) colors. LED's are available in COOL or middle of the road (4000-5000K) "Neutral" range, while incandescent bulb output is typically WARM. 

Q: Cool White/6300K or Neutral White/4300K Color LED?
A: Bright bluish~COOL LED have been around for a while, but due to recent developments in LED technology - we now have a choice in tint and color rendering - with the high efficiency of LED!
Output color is a personal preference - some people don't like the bluish~COOL color of LED preferring the yellowish color warm light from a typical incandescent bulb, and some people don't like the yellowish/white color of an incandescent bulb preferring the look of typical fluorescent lighting.

All things considered (similar lumen output) most people prefer:

NOTE: Today's LED tint offerings are not quite as extreme as the above pics show (COOL is now less blue, NEUTRAL is now less yellow) - but the above is a quick visual to "see" the differences between the two tints...

NOTE2: Every monitor/device displays colors differently, and every monitor/device typically has been user adjusted based on the users personal preferences - the above pictures were taken using a standard "daylight" setting on camera - and may display on your monitor slightly more or less Cool/Warm than in actuality. (on our color calibrated systems, these pics look like what we "see" in person)

Q: Which tint should I get - COOL or NEUTRAL?
A:  Tint Color and Color Rendition can be a very subjective matter. Different tint Color and rendition may be preferred for different applications, and different people will have varied color preferences!

Q: What is CRI - Color Rendering?
A: CRI is a quantitative measure of the ability of a light source to reproduce the colors of various objects faithfully in comparison with an ideal or natural light source. The Color Rendering Index (CRI) is a scale from 0 to 100 percent indicating how accurate a "given" light source is at rendering visible colors when compared to a "reference" light source.
Light sources with high CRI are desirable in color-critical applications such as photography, cinematography, medical users, aircraft mechanics and the like - people who need/desire to reproduce the colors of various objects more faithfully/correctly.
NOTE: CRI can be independent of Tint/Color Temperature
(EX. there are Neutral and Warm tint lights with High CRI, and there are also Cool Tint lights with High CRI). Also, generally a low CRI light has a lot more lumens than a comparable high CRI light. 

A light producing a Neutral Tint (4500-5000K), with CRI above 90 is considered ideal.

Q: I don't care about tint color, I just want brightest?
A: COOL LED are still leading in lumen output over NEUTRAL LED, but not by much anymore. 
With today's high output LED - NEUTRAL tint can now be as close as 6-7% of the Lumen output of similar Cool White LED, and human eyes typically can't see less than 30% difference in lumen output.
But, output TINT/Color differences will be very obvious, one being bluish, while other is yellowish. 
Interestingly - when a user compares two identical flashlight using identical reflectors - one with Cool White LED, and one with Neutral White - our BRAIN says the yellowish NEUTRAL is MUCH dimmer than the bluish COOL... but look again, most users can actually see a lot better and clearer with the NEUTRAL light.

Q: I am color blind - will this make a difference?
A: Absolutely! About 8 percent of males, and 0.5 percent of females, are color blind in some way or another, whether it is one color, or a color combination... this effects how the user "sees" and uses light.
Generally, a color blind user will not see the benefits of the different color tints - and just goes with brighter cool tint regardless of their intended use, or, will use a tint that looks best to them (one of our customers says NEUTRAL looks significantly brighter to him!).

Not sure if you are Color Blind? Here is a quick test... Ishihara Color Test

Interesting BBC News article: Do you See What I see? http://www.bbc.co.uk/news/science-environment-14421303
Can you trust your eyes/Brain? Amazing shade illusion will make you see the light. http://games.yahoo.com/blogs/plugged-in/amazing-shade-illusion-see-light-024226513.html
And another Brain Twister. How Many Black Dots Illusion http://www.iflscience.com/brain/this-12-black-dot-illusion-is-blowing-a-lot-of-minds/

Q: Can the tint/output be altered?
A: Certainly - by using Colored Lens/Filters - one can temporarily change the output tint/color to just about any color desired - though at a bit of a loss in output. Common Filters that can be purchased are Diffuser, Yellow/Amber, Red, Green, Blue.
Want more tint options? http://www.leefilters.com/lighting/colour-list.html#
Check out the several hundred sheets of 3.5"x1.5" Lee Filters/Swatch book that can be purchased (from Lee filters) for a few $, giving you virtually unlimited output colors from your light (cut filter disks to size and insert in front or behind light lens). 
More Info: http://www.candlepowerforums.com/vb/showthread.php?320811-Changing-LED-Tint-With-Filters
and  LEE Filters Designer Swatch Book


Q: Why is this xxx Lumen Light not as bright as my other xxx Lumen Light?

A: Very subjective, it all depends on how the light output was measured, how the light output is focused, the Color Temperature, and, how YOUR eyes see it...
but let's first define some common terms:

LUMENS, Bulb Lumens/Emitter Lumens/LED Lumens = amount of light being produced and measured at the surface of the LED.
OTF Lumens = amount of light being produced and measured coming Out~The~Front of light (this accounts for loses with reflector and lens, 20-30% loss is typical).
ANSI LUMENS = amount of light being produced, and measured OTF of light after a specified amount of time - usually 2-3 minutes. 
(We compare Lumens and OTF/ANSI Lumens, to Automotive Crank/Engine Horsepower and Rear wheel/brake Horsepower)

Brightness = LUX, A measure of the intensity of the center spot.
Throw = how far the beam reaches.

Q. How much LUX do I need? 
A. A good observation/baseline provided by our LEO/Military users: "7,500 LUX, allows them to count fingers at 75 meters"!
But note, 2x LUX does not produce 2x throw. LUX to throw generally speaking, has a 2 to 1 ratio (2x LUX, provides approx 50% more throw). Search the internet for "inverse-square law of light", for a full scientific explanation. ;P

Common Misconception: More Lumens makes more throw. No, not necessarily, it is the focus of output, the size of the reflector/head, and, the lumens that creates more throw. (We have several lower lumen lights that outthrow some of the higher lumen ones!)

EX: In the household, a 100w light bulb, vs 100w flood light, vs 100w spot light all create 100 watts of light,
ie. they are all the same lumens of a 100w bulb, but the output beam appearance and use is completely dependent on how the light output is focused (area light, vs flood, vs spot).

With flashlights ~ Lumens only tells you how much light is being produced, not how it is focused, by adding LUX to the equation one can determine what type of output should be expected when compared to another light... EX: more floody vs more throwy etc.

More Info http://flashlightwiki.com/Main_Page

TIP: A quick and easy way for any user to more objectively compare one light to another light without testing equipment is to perform a "ceiling bounce test". 
In a darkened room (bedroom, living room, etc) ~ point flashlight up to center of ceiling, while you look down to floor, then switch light ON... look at the amount of light reflected down to the floor, wall, and surrounding area. Do this/compare with another light ~ and you can quickly determine the amount of light being produced with one light vs another light.