No one has replied in a while so I'll give it a shot. Lumens are the total amount of light produced by the light(measuring the entire beam emitted). Candlepower is the intensity of light when the measurement device is held in a single portion of the light beam.
Two lights for example may both put out 3000 lumens(something like an HID Harbor Freight), but lets say the H.F. light has a narrow beam and the other hipothetical(sp) light has a wide flood beam. They both produce 3000 lumens but the Harbor Freight would show more Candlepower as measured in its beam because the light is more focused on the measuring device.
There is no direct corelation between candlepower and lumens from what I understand.
LEDs can be quite bright but you may notice they don't seem to have the long distance illumination(throw) that HIDs have. This is because the LEDs do not have as small a point of light(emittance) as an HID. The larger glowing area of the LED cannot be focused as well as the smaller point of illumance of an HID. A larger reflector(or higher quality) can help with throw but still not enough. Not to mention a reflector can SEE more of the HID point of light(think sphere of light comming from the HID point source) than from the LED emmiting light from only its front surface.
A VERY small point of light like a short arc(Maxabeam) can be focused even farther and have fantastic throw.
So a bunch of high output LEDs could never have the throw of an HID I beleve but could be eventually focused through optics to give 15 M c.p. but it would be ugly
**EDIT** Take a look at NewBie's thread on "How to make a CREE throw"
The cheap Costco/Sam's 15 M c.p. <$30.00 use lead acid batteries as do the cheaper HIDs (Costco/H.F.) More expensive lights use Nickel Metal Hydride or Lithium Polimer.
I hope that helps. Someone with more knowledge hopefully will come along and correct any errors I made *hehe*
NOTE: Any errors in spelling, grammar and/or logic are the sole fault of Windows Vista and Bablefish and the cat hitting my keyboard.....
/////////-----Warning !! Catlike typing detected htehghs....sdsfjfd
