Ohh So is lumens based on the TOTAL output and not a given area?
Yep
(luminous flux), google "
integrating sphere" and you'll find the device used for measuring the total light output of a light source. As the term "integrating" implies, it's total output (remember integrals in maths, loooong ago?).
So when a 100w bulb says it is 1600 lumens, that is the total light going in almost all directions, while a LED that says is 500 lumens they are more concentrated into a certain direction so it would seem like more light?
Basically, that's it.
As an example: I have a luminaire hanging over my table with a E27 socket facing down, so the lamp base will be vertical and pointed towards the ceiling.
I tried a good old incandescent of 630 lm and compared it with a retrofit LED bulb which has the LEDs on a flat pcb facing down. That retrofit LED bulb was specced at 470 lm.
In this application, the LED bulb clearly threw more light on the table, even though it was the weaker one. The light was directed at the table.
That's why I don't like retrofit LED bulbs very much. By trying to emulate an incandescent bulb, they waste a lot of available light.
IMHO, the "classic" LED (i.e. the square or round chips) are best used for directional lighting. If you do need unidirectional from a LED bulb, then a LED filament bulb does a better job. At first I was suspicious obout their life span, but now big brands (e.g. Osram and Philips) deem them good enough to sell them under their own names.
Interestingly I also found these through hole LEDs that appear to be insanely bright:
http://www.cree.com/LED-Components-and-Modules/Products/High-Brightness/4mm-Oval-P2/Screen-Master-4mm-Oval-RGB
Some are like 1500 lumens at 20ma, does that make sense? I must be reading that data wrong. Maybe the typical value means when there are a lot of them together?
No, those are not lumens, they're mcd, milli
candela and as rs20 explained, they're different units. mcd is light intensity. And yes, that's a rather useless unit for comparison.
From wikipedia: "1
lx = 1 lm/m
2 = 1 cd·sr/m
2".
Light intensity of two different light sources can only be compared when they've got the exact same specs for radiation angle and measuring distance from the source.
Example: two light sources have the same amount of luminous flux but one of them as a a radiation angle that's narrow, the other wide. When measured from the same distance, and in the centre of the beam, the narrow beam will result in a higher reading than the wide beam. But then, (i.e.) 45 degrees off centre, the narrow beam may be reading less than the wide beam...
So yes, a narrow beam of less total light output may indeed seem brighter (in the lit area) than a wide beam light. Apples and pears...
It's probably why EU regulators first made regulations for unidirectional light sources and left the directional light sources out. Now the directional light sources must also be specified by the manufacturers in lumen and they must specify only the light in a cone of 90 degrees (there are exceptions). All light that falls outside that cone must not be specified.
All of a sudded we found that a 50 W halogen spot light had less light output than a bog standard 40 W bulb? What? Apples and pears..., you can't compare them...
Long story short... it all boils down to choosing the right beam angle for the application and then choosing the right amount of light output for the job.
Did a bit more digging and none of the xlamp XM-L modules even come close to 2000 lumens, so are most flash light manufacturers just outright lying? Most LED flash light seem to be in the thousand lumens range.
2000 lm is a hell of a lot of light, it looks like they used the wrong unit in the flash light ad. If they meant lx, then it says nothing without knowing how far from the light source it was measured. I can easily make my lux meter "think" it's seeing direct sunlight by sticking the flashlight up close to the sensor. It will then read O.L. as it's over it's limit of 40,000 lx (direct sunlight is over 100,000 lx).