Are these lumens or candlepower units

My name is Neil and I'm additted to flashlights..that new UltraStinger pushed me over the edge..so in my thirst for my new passion I'm in need of a little help understanding beam measurement...I'd like to use a mind exercise to see if I'm right in my understanding...you are on the bottom of a river with heavy sediment.. 3 inch visibiliy...now call up for power to your 230v-9,000 "Lumen" HID...with its 2%focus.. is that 4 inch wide "laser" beam projecting 6 feet ahead of you the "lumen" protons...and as the "hot spot" states to bring your project into view at about 2 feet... those protons lighting the object or the candlepower guys..Do I know this out in very elementery correct in my mind.

Lumens is a measure of the total amount of light generated at visible frequencies. CP is a measure of the amount striking a small target at a specific distance.

Others will have to be more precise. I recently compared a SureFire Z3/HOLA to a custom Megaclops from lambda. The Z3 clearly put out more light and therefore I expect a higher lumen measurement. But the Megaclops could find mailboxes further down the street due to its tighter focus and therefore may well have a higher lux or foot-candle rating.

So, is "lux" the same as "candlepower?"

EDIT: whoops, mental lapse. Jonathan gives correct and more thorough explaination below.

So basically I have the concept.... Lumens equal total output as.. the 6 foot laser affect..and the CP is the measurement of the protons lighting up my object....I just may have it now.

Not quite correct.

The Lumen is the measurement of the total light output without directional information. It is a quantity of light (in roughly the same way that a gallon is a quantity of water).

The Candela is the measurement of the _intensity_ of light, usually in a particular _direction_. It is measured in terms of quantity of light per unit of solid angle. When you see a spotlight rated as 1 million candlepower, that means that in the bright part of the beam the intensity of light is 1 million lumens per steradian. (Note: the actual size of the beam is much less than 1 steradian, so that you don't have 1 million lumen. It is just like a car that gets 20 miles to the gallon when you only drive 1 mile.)

The Lux is the measurement of the light crossing a particular _area_, or light falling on a particular area. It is measured in terms of quantity of light per unit area.

They are all related by different measurements of space. A steradian is a measure of solid angle (think of a cone radiating from your light source.) The definition of a steradian is that on a sphere a cone with a solid angle of 1 radian with the tip right at the center of the sphere would cut out an area on the surface of the sphere equal to a square with a side that is the same as the radius of that sphere (whew!) Roughly if you have a cone with a solid angle of 1 steradian, it will cut 1 m^2 at a distance of 1 meter.

So if you have a light source that puts out 1 lumen/steradian (1 candela) then at a distance of 1 meter that light source will lay down 1 lumen/m^2, or 1 Lux at 1 Meter means an intensity of 1 Candela.

-Jon