What is the lumen effeciency or lumens?
241307
Don't know the lumens but it is quite bright and adjustable from dim to bright.
802246
It should be noted that "lumen" can mean many things depending on how you obtain a lumen measurement. At one foot away with the "zoom" at max spread the light produced 4800~4900 lux which is about 450 lumens/sq ft. Though when focus to a point the light produced over 90,000 lux which is about 8,300 lumens/sq ft. Unless you can find definitive data that explains the lumen of this light (or any other light in existence) the advertised brightness of a flashlight is meaningless. It's would be better to look up the datasheet for the Cree XML emitter and search for visual examples of the light (using quality 3.7V 18650 Li-Ion bats of course).
194578
Not sure of the reason for the variance. From what I understand, if you use rechargable lithium batteries, you'll achieve maximum lumen output.
189267
10W * 100 LM/W = 1000 Lumen (but this does not account for dispersion etc.)But, let's say current draw yields only 6 watt, and let's say efficiency is less at the 90 LM/W, then this gives 540 Lumen. A 100 W incandescent (bulb that is becoming obsolete) is about 1200 Lumen.To really account for dispersion of light and other factors, divide each of these Lumen by about 4. Incandescent rates about a little above 300 Lumen.
1790323
A given amount of light will illuminate a surface more dimly if it is spread over a larger area, so illuminance (lux) is inversely proportional to area when the luminous flux (lumens) is held constant. One lux is equal to one lumen per square metre: 1 lx = 1 lm/m2 = 1 cd.
479525
Hi Evan, I still have the light in it's original box, but it does not indicate Lumens. In fairness though, I've had it so long that the newer labels may reflect the Lumens number. Regardless, the unit lights up the engine area well, but it is just a standard socket, so you could buy a hotter one if you felt it was needed. Finally, this tool is excellent and is everything it advertised. Regards, Rossi
1125893
According to the Wikipedia entry on 'Incandescent light bulb': "The luminous efficacy of a typical incandescent bulb is 16 lumens per watt, compared to the 60 lm/W of a compact fluorescent bulb."That would mean 20 lumens is about the same as a 1.25 watt incandescent bulb -- slightly less than 1/3 the light of a 4watt small incandescent nightlight. That's the theory anyway...
323083
The Lumens show how much light the flashlight will put out. The higher the lumens, the brighter it will be. It's bright enough to get someones attention, but it doesn't go the distance since it widens out the farther i shine it.
1284988
I am pretty sure it is very low, led's don't put out many lumens. Lumens is a measure of light humans see. Par is what plants see. I found a watt to lumen calculator online. Seems to be about 18,000 lumens, From what it says a 300 watt led puts out.
1507290
Not sure about the lumens capacity but it is probably the brightest regular bulb on the market. LEDs may be brighter though.
293008
This model is 500 lumens. I doubt you would be able to tell the difference between the two different powers.
141804
I'm not sure what the lumens are because I bought it for a gift. All I know is that they were bright and my brother in law is very happy with them.
63026
I don't know number of lumen but my flashlight stopped working after a few months. As their promise " lifefetime warra ty", they are very responsive and concern immediately sent me a new one. I am very please and satisfied.Saeree J.
1014688
I have no idea what the lumens are. However, at in the late night, when I narrow the beam to it's smallest I can see a 4' x 4' area 200' away, very clear . That is very good for a flash light with one AA battery that last a long time.S. R. Kirkley Tyler, TX
861865
I don't know the actual number of lumens. However each light has two LEDs and the light is considerably brighter than the other patio/pathway lights I have had. Personally, I wouldn't want them to be any brighter, they light up the walk quite well.
1781570
I don't know what lumens are, but it gives outnext to nothing in light. If you expect to see by this light, don't buy it.
344932
No idea of the lumen output but they are considerably brighter and whiter than my headlight adding a lot of useful light when driving at night