[Beastmaster]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by ree:
Steve,
How does all this lumen stuff relate to candlepower. Putting on lights recently, I researched state laws for home and surrounding states and they all have statutes talking about 300 candlepower limits on all lights in operation. Isn't candlepower luminous intensity? How can you get from a manufacturers rating wattage and lumens ratings to candlepower accurately, or can you?

Basically, are these statutes ancient cruft or something that the states can actually prosecute you on? </div></BLOCKQUOTE>

It's kind of crap. Here's the relationship.

Lumens is a definition as to how bright a light is. It's measured within a device called an "integrating sphere", and identical lights will have nearly identical lumen values.

Candlepower is a measurement of the amount of light intensity based upon a specific distance. It's also dependent on how focused the beam is and how far away your measurement tool is from the light source.

Candlepower figures are useful only when you have lumen figures to compare with it. For example:

You have a KC Hilite HID light that's pencil beam, and you have another KC Hilite HID light that's driving beam. The Pencil beam and driving beam both use the same D2S bulb, so both have the same lumen rating.

However, the Candlepower settings are different. Pencil gives you 3 million CP, the driving beam gives only 750k CP. The difference is the focus.

So CP really is how intense the light focus is given a specific area, Lumens is how bright the light actually is based on the bulb itself.


Correction - Pencil gives 600k, Driving gives 75k.