PDA

View Full Version : Lumens



madman
03-28-2005, 02:35 PM
Does anyone know the differance from Lumens Candlepower Foot Candles and MCD s. I am trying to figure out how to accurately figure out which flashlight is better brighter than its competetors. Quite confusing for me at least. Thanx

ERBenoit
03-28-2005, 02:53 PM
I have a hand book of reference tables that has some lumens formulas in it. No lighting engineer. I do not know exactly what you are looking for, how many of this = that, or this in comparison to that. I do not know what an "MCD" is either, except for the "golden arches".

John Stevenson
03-28-2005, 03:13 PM
1 foot candle = 10.76391 meter-candles

bikenut
03-28-2005, 03:17 PM
Take the flashlights and shine them into your eye, the one that blinds you the best is the one to buy. Smitty

Angus in Maine
03-28-2005, 04:09 PM
Smitty...

Is that what they call a "blind comparison"?

debequem
03-28-2005, 04:31 PM
Try searchin on the interney "Lumans to Candles", etc. There are plenty of those conversion engines available.

Marv

andy_b
03-28-2005, 09:05 PM
madman,

what you ask cannot be done. on several of the message boards and newsgroups i've been on over the years this topic comes up quite frequently. the last million-reply thread on it was on the rec.guns newsgroup when guys were trying to decide which tactical flashlight to purchase.

the problem is that a candlepower is a unit of measurement describing the light output from a point source based on an archaic standard of "one candle power". a lumen is the measurement of a light's intensity over a given area. a flashlight of 1000 candlepower will have a different lumen value depending upon how far away from the light source the measurement is taken. think of it this way, if you are 1" from a light, it is very bright, if you are 10' from it, the light cast on to a surface (the lumen value) is much less, but the candlepower of the source has not changed.

andy b.

halac
03-28-2005, 10:17 PM
According to my "Pocket Reference":

To convert from candle power to lumens you multiply by 12.566

I know this is what we use at work when we calibrate light meters.

Hal C. , www.tempyramid.com (http://www.tempyramid.com)

madman
03-29-2005, 02:38 PM
Hey Smitty Ill just take youre advice but Ill shine the light in someone elses eyes. II ll probably use one of the kids.

JPR
03-29-2005, 03:03 PM
here is the free conversion program that I use http://www.joshmadison.com/software/convert/