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    RickJ's Avatar
    RickJ Posts: 7,762, Reputation: 864
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    #1

    Nov 2, 2006, 03:48 AM
    LED Flashlights: Lumens, Candlepower & lux
    Boo hoo hoo I've lost my favorite flashlight: a 3-C 9-watt (Three 3-Watt bulbs) model that went with me everywhere.

    1. Lumens, Candlepower & lux confuses the heck out of me, and
    2. It seems apparent that not all 3-watt bulbs are equal.

    I want to stick with LED - and I prefer a 3-C or 4-C as far as body size goes... so what should I look for?

    I'm looking at this 400 lumen 4-C model but wonder: Can I find brighter?

    ... is there a brand that is on the cutting edge of LED lights that in the flashlight industry "just can't be beat".

    Any suggestions?

    Thanks!
    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
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    #2

    Nov 2, 2006, 04:23 AM
    Quote Originally Posted by RickJ
    Is one of the better written explanations of lighting values I have seen, make perfect sense.

    What is it that your not sure of?

    And what a coincidence, I see there is a flashlight expert recently on board!

    Just to help with what should be considered and condense the white paper, since a flashlight and the type of lamp typically used is a "point source", try to get the most or highest candlepower available, if the unit is rated as such.

    The quality and characteristic of a reflector is also important , since a lamp, "light bulb" (the glass envelope is really the bulb) is fairly useless without one. Using a point source lamp, and a reflector, then gives values called beam lumens, beam angle, and combined is beam component.

    This is what provides that "punch of light" to a light fixture.

    The Model 400 Lumen 4C unit you refer to does not seem to be rated in beam component, however, with the sample photos, is trying to illustrate the better beam of light it has compared to another unit.

    So, my point is not just to look at candlepower but look at the reflector combined with the lamp.

    I am very excited to see the inroads LED technology has come so far, and what will come in the future.
    RickJ's Avatar
    RickJ Posts: 7,762, Reputation: 864
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    #3

    Nov 2, 2006, 05:15 AM
    Thanks, tk. I did post this seeing the "new guy" come aboard yesterday.

    The confusion really is that
    1. Some flashlights only give candlepower and some only give lumens. The two do not seem to be the same sort of rating. In other words; not as simple as saying how many candlepower equals a lumen.
    2. Then some add a lux rating.

    I read this article twice and my head is spinning...
    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
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    #4

    Nov 2, 2006, 07:23 AM
    OK First, Lux is metric version of measuring light. So set that to the side.

    I do find that they mis-spoke in the paper in "Summing it all up":
    Lumens are a metric equivalent to foot-candles
    Just to add to your confusion.


    OK, from the white paper:

    So, that one candlepower equivalent equals 12.57 lumens.

    Probably the simplest I can put it, using the white paper as a reference, is candlepower is the light directly at the source, (light bulb), and 1 lumen is the amount of light in a one foot square , 1 foot away from the source.

    So, seems that some units noting candlepower, is at the bulb, and some use lumens, which is the amount of light some distance away.

    Again, to help clarify, this lumen rating is due to the bulb AND the reflector.

    A source may have a great candlepower rating, but a poor lumen rating because of a sub-standard or poorly designed or made reflector.

    Getting there?
    bhayne's Avatar
    bhayne Posts: 339, Reputation: 4
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    #5

    Nov 2, 2006, 07:25 AM
    1. Lumens, Candlepower & lux confuses the heck out of me, and
    2. It seems apparent that not all 3-watt bulbs are equal

    Watts is the only measurement available for a flashlight unless it specifies the background color and distance from an object (preferably a volume is given or assumed infinite). Candles or Illuminance are interchagable as Imperial or Metric measurement. Also you don't measue the light source, you measure the reflected light at a specified distance.

    So it may be 2 candles (or 20 lux) at 1 foot on a white background. That is much less that 1 candle at 2 feet on a white background. Which is less than 1 candle at 1 foot on a black background.

    I see number 1. above as a useless measurement for a flashlight!
    RickJ's Avatar
    RickJ Posts: 7,762, Reputation: 864
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    #6

    Nov 2, 2006, 07:40 AM
    Thanks, tk. Makes much more sense now.

    Quote Originally Posted by bhayne
    Watts is the only measurement available for a flashlight unless it specifies the background color and distance from an object.
    ??
    Many flashlights give lumens or candlepower but NOT watts. Thankfully, the higher end flashlights do give watts, but that leaves the final question, then.

    Presuming an identical reflector, do all 3-watt LED bulbs put out equal light?
    omzig's Avatar
    omzig Posts: 119, Reputation: 19
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    #7

    Nov 2, 2006, 07:46 AM
    It's not LED, but I've got one of these: Big D and it is awesome. I left it on the bumper if my truck last week and drove off. I looked in the rear view mirror and saw it tumbling down the street. It had a few scratches but still works fine.

    Anyway, BrightGuy.com also has some pretty good info on lumens, candlepower, etc. here: http://www.brightguy.com/brighttopics.php
    bhayne's Avatar
    bhayne Posts: 339, Reputation: 4
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    #8

    Nov 2, 2006, 08:08 AM
    Quote Originally Posted by RickJ
    Presuming an identical reflector, do all 3-watt LED bulbs put out equal light?

    I think the only way to tell is to shine them into the same box and measure the reflected light.

    Most high end lights have a light dispersion pattern that will optimize the light to the source (narrow spread pattern for detailed tasks on close objects or wide spread pattern (flood pattern) for searching over a large area). I would recommend these types of flashlights.
    RickJ's Avatar
    RickJ Posts: 7,762, Reputation: 864
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    #9

    Nov 2, 2006, 08:25 AM
    Yes, on most of the ones I have I can rotate the head to pull the bulb away from or closer to the reflector to make it be more focused - or spread out.
    omzig's Avatar
    omzig Posts: 119, Reputation: 19
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    #10

    Nov 2, 2006, 02:36 PM
    @RickJ, The Elektro Lumens flashlights look great. I'm thinking of ordering one of the K2-Stunners. BTW, if the QuadStar Phazer is the one that you end up going with, you might be in for a wait. That picture is a prototype and it doesn't look like he has made any of them yet. Did you see this? http://elektrolumens.com/Status.htm
    RickJ's Avatar
    RickJ Posts: 7,762, Reputation: 864
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    #11

    Nov 3, 2006, 05:33 AM
    Yes, and that was the case with the one I lost. At the time I purchased it, it was the most powerful one they had... and it had to be pre-ordered. It's not on their site now: It was a 3-C model with Three 3-watt bulbs.

    I remember doing A lot of surfing the web before I decided on them... and at the time it seemed that they were out there in the forefront of high power LED lights.

    I can say this. Their stuff is HIGH quality. I still have the XM-3: single 3-Watt 2-AA light that is built like a tank. I could hammer nails with it. The one I lost could beat a Mag Light to shrapnel. :p
    Heyimjack's Avatar
    Heyimjack Posts: 1, Reputation: 1
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    #12

    Jul 27, 2007, 02:52 PM
    Quote Originally Posted by RickJ
    Boo hoo hoo I've lost my favorite flashlight: a 3-C 9-watt (Three 3-Watt bulbs) model that went with me everywhere.

    1. Lumens, Candlepower & lux confuses the heck out of me, and
    2. It seems apparent that not all 3-watt bulbs are equal.

    I want to stick with LED - and I prefer a 3-C or 4-C as far as body size goes...so what should I look for?

    I'm looking at this 400 lumen 4-C model but wonder: Can I find brighter?

    ...is there a brand that is on the cutting edge of LED lights that in the flashlight industry "just can't be beat".

    Any suggestions?

    Thanks!!
    I just read the post and I'm sure you already replaced your old LED light, but I wanted to make sure you knew about the Wolf-Eyes brand of flashlights. We purchased some of them to compare with our lights a few months back and they are extremely impressive. The Elektrolumens light you were looking at appears to simply be 4 Seoul LEDs put together in one head assembly. That won't really make it that much brighter/reach any further in the dark. In my opinion, the light will probably end up around 150-200 lumens rather than the 800+ they advertise. The difference between a 1 Seould LED light and this 4 version would be that it does have a slightly "wider" beam.

    wolf-eyes.com

    And just in case you want to check out OUR lights
    Smith & Wesson® Flashlights Official Homepage

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