Lumens meaning

Hi guys. I would like some information and I know you experts will be able to help me out. I was recently debating about getting a PT Rage or PT Tec40. I eventually went with the Tec40 but have a few questions about brightness. Some of you told me that the Tec40 was about twice as bright as the Rage. This confuses me since the Rage has a 41 lumens rating and the Tec40 has a 28 lumens rating. I always thought the lumens was your brightness, am I wrong? On the flip side, the Rage has 2.6 watts of power whereas the Tec40 has 4 watts of power. Is the wattage all that matters? Thanks for any input.

Lumen \Lu"men\, n.; pl. L. Lumina, E. Lumens. [L., light, an opening for light.] 1. (Photom.) (a) A unit of illumination, being the amount of illumination of a unit area of spherical surface, due to a light of unit intensity placed at the center of the sphere. (b) A unit of light flux, being the flux through one square meter of surface the illumination of which is uniform and of unit brightness.


And try a Search for Lumens and/or Candlepower. There's good info in the posts about this...

--dan

The lumen readings you have for those lights must have been switched. It is probably 41 lumens for the Tec 40 and 28 for the Rage. Also, different manufacturers measure lumens differently, so don't just go by a manufacturer's claim.

Lumen is a measurement of the total ammount of light given. Candlepower measures the brightness.

Hate to refer to another forum, but this bunch of threads is excellent:

http://186thousand.com/cgi-bin/ultimatebb.cgi?ubb=forum;f=15

You can get a general description from the following flashlight reviewer's website here.

Now if you want a very in depth understanding on what a lumen is (very technical information here, possibly requiring advanced knowledge of mathematics) click here.

In laymens terms, Lumens is measure of the total light output in all directions.

This can be very confusing since a light that puts out a very tight beam may appear to be brighter than a light that puts out a wide area [flood] of light, even though the total lumens of the tight beam is less than the total lumens of the flood light.

Hope that less tecnical description helps.

If you look at the link posted by JohnK, you'll notice my little mini-rant about using lumens for rating the brightness of lights. Besides looking at the high ratings of normal lightbulbs, you can look at a SureFire light for another example of the folly of relying purely on the lumen ratings. Take two SureFires, say an M3 and an M3T with the lamps that have the same ratings, 125 (?) or so. The output is exactly the same, but the turbohead is brighter and throws further, but in a tighter beam. Lumens by itself is useless to determine which one to get without some other measurement of brightness, or better yet beamshots.

Ah... the Rage vs Tec40 Lumens issue again....

The Rage - a 4 AAA light supposedly puts out more lumens (overall light) than the Tec40, a 4 AA light.

Frankly, I still think somebody screwed up on their end and misinterepreted some numbers from the bulb manufacturers, but that's what their numbers say.

Shine them both on a wall however, side-by-side, and the Tec40 appears to put out much more light overall...