That's actually great information right there! Thanks! But another question....how could I make my own off road light by taking a single strong LED and making a housing and using it as a light...what would I need?
Your first concern would have to be towards a housing that could dissipate the amount of heat generated by such an LED, which can be quite a bit. You'll also need to make it watertight and somewhat shockproof. Then comes the focusing of the beam, but how you do that will depend upon the type and shape of beam you're looking for. Spots, floods, diffused, driving and fog beams all have different shapes and patterns, and those shapes and patterns in turn dictate the shape and design of the reflectors and lenses used, as well as the distance from the LED to the reflector.
In short, it can be done, but you'll need to either study up on the physics involved, or do a lot of testing and experimentation.
Much simpler, and probably cheaper, IMHO, to simply purchase a commercially made LED light suitable for what you want. There's a lot of companies out there making them now, and many of the Chinese imports are really quite good, which has driven the price way down in recent years.
These guys make some of the best (and most expensive) and would be a good starting point:
http://www.rigidindustries.com/Default.asp
I have a pair of these mounted on the back of my truck and they work quite well for wide area work lights:
http://www.ebay.com/itm/190636907028?ssPageName=STRK:MEWAX:VRI&_trksid=p3984.m1423.l2661
Here's a pic of them in action
DSCN0555 by
bwbehling, on Flickr
Just to put things in perspective, that streak of light on the left edge of the photo is a 250w mercury vapor street light, and that point of light on the right side, just above the hood of the Mercury Mountaineer is a Coleman gas lantern outside a tent about 25' behind the Mercury. The red lights are 6 strings (100 each) of red LED Christmas lights. Yeah, those fwonking floods are
bright.