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Thread: Some questions

  1. #1

    Default Some questions

    Hi everybody,

    I have some questions about flashlights, car headlights, and other,

    1 I have a spotlight LiteXpress LXSP 102 with 210 lumens on high and 20 lumens on low, and a beamdistance of 240 meters on low, and a stunning 670 meters on high,

    What does the beamdistance mean? Does it illuminate things at 670 meters distance, in absolute darkness?


    See Rule #3 Do not Hot Link images. Please host on an image site, Imageshack or similar and repost – Thanks Norm
    Last edited by Norm; 01-08-2013 at 01:18 PM.

  2. #2
    Flashaholic* AnAppleSnail's Avatar
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    Default Re: Some questions

    It might do that. It means that objects at that distance are lit to 0.25 lux, or 0.25 lumen per square meter. This is half of how bright a full moon is. Can you see something at 678m by half-moonlight? Probably not. The ANSI standard isn't perfect, but it does give us some comparison. I think I find about 1/3 the ANSI distance to be the useful seeing distance in many situations... But sometimes you'll see reflectors at twice that distance, or be unable to see a tenth that far.

    On a clear night, without light pollution, without nearby objects to be over-lit by the flashlight, you could probably spot a contrasting object or building at about that range. But you probably wouldn't identify a person, distinguished hiding animals, or identify trees.
    My biggest light-hog is my camera.

  3. #3

    Default Re: Some questions

    2 Does it mean, the more lumens, the more beamdistance? Or is it the more beamintensity, the more distance for throw?

    3 What is the brightest handheld spotlight you can buy on the internet? Greatest beamdistance/lumens? LED/Incandecent/HID?

    4 What is the average beamdistance of car headlights? Incandecent halogen, and the superbright HID Xenon headlights on modern cars, like BMW, Audi, Volvo? When lights are set on high beams?

    Thanks for all who will help me with this questions.

    Remco

  4. #4
    Flashaholic* AnAppleSnail's Avatar
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    Default Re: Some questions

    Beam distance is intensity. A house lightbulb can be 1600 lumens, but won't reach as far as a 4 lumen old mag lite. Generally, a big reflector and a small light source make more intensity.

    The brightest? Stanley 10W spotlight, or go to OneStopThrowShop, or buy a 'zoomy' (aspheric) light, or...

    Depends on the car, the voltage, the fog, the bulb age... Call each (legal!) lamp 750-1000 lumen output and a range of about 100m.
    My biggest light-hog is my camera.

  5. #5
    *Flashaholic*
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    Default Re: Some questions

    The cd number tells you how FAR the beam can reach, and the lumen number tells you the total out put of the light.

    You can't see lumens...lumens are what the light sends OUT.

    If the photons the lumens are describing don't hit something and bounce back to your eye...you see nothing.


    Lux is a measure of how much light is bounced back to your eyes, essentially, how bright the TARGET looks to you.

    The light meter in a camera is essentially measuring lux for example....to help determine the correct exposure, etc.


    cd is the same as the Lux at one meter...as if you put that light meter that measures lux one meter from the light, and shined the light at the meter.


    There are equations that can calculate the lux at OTHER distances if you know the lux at ONE distance, so the cd is used to calculate how far the beam goes before you could only SEE targets lit up at 0.25 lux.


    So when a light has very high cd numbers, and very low lumen numbers, it means the beam is very very concentrated....and the spot of light you SEE at those ranges will be teeny.

    Another light might have even a THOUSAND times your light's lumens, but not the cd needed to throw those lumens as far away.



    Imagine a garden hose, and the water flowing out in a wide stream pouring onto the lawn a few feet away....maybe 5 gallons/minute, but landing 4' away.

    Now, put your thumb over the end of the hose....so it sends the thin stream of water 40' away instead of 4' away...but only a small thin, concentrated stream, not a fat flood pouring out as before.


    That's what the lens/reflector of the light is doing, putting its thumb on the stream...and making it either floody, or, concentrated, etc.



  6. #6

    Default Re: Some questions

    Quote Originally Posted by AnAppleSnail View Post
    Beam distance is intensity. A house lightbulb can be 1600 lumens, but won't reach as far as a 4 lumen old mag lite. Generally, a big reflector and a small light source make more intensity.

    The brightest? Stanley 10W spotlight, or go to OneStopThrowShop, or buy a 'zoomy' (aspheric) light, or...

    Depends on the car, the voltage, the fog, the bulb age... Call each (legal!) lamp 750-1000 lumen output and a range of about 100m.
    Thank you for helping me with the questions,

    1 When shining straight forward, a average halogen car headlight shines about 500 meters i think, and a high power HID Xenon car headlight on a very expensive BMW can reach near 1000 metres ? You wrote 100 meters, but thats wrong i think, every type of carheadlights goes well over 100 meters.

    2 Does my led spotlight with beamdistance of 670 meters, illuminate things at 1 kilometer/1000 meters distance?

    3 What do i see when you shines towards me ,with my 210 lumen, 670 meters beamdistance spotlight, in a clear night, when i am at 670 ,and 1000 meters away from you?

    4 Why is the beamdistance less far ,when it is cloudy, and haze?

    Remco

  7. #7
    Flashaholic* HighlanderNorth's Avatar
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    Default Re: Some questions

    I have some serious difficulty believing that a 210 lumen light pushes 115,000cd. Or that at 20L it pushes 10,000cd. I could be wrong but I think the specs are greatly exaggerated by the manufacturer. I've never heard of a 200L light with that kinda throw potential. Even the TN31, which is one of the top throwers has 1150 lumens but with only 75,000cd.
    Some days you are the bug, some days you are the windshield.

  8. #8
    *Flashaholic*
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    Default Re: Some questions

    Quote Originally Posted by HighlanderNorth View Post
    I have some serious difficulty believing that a 210 lumen light pushes 115,000cd. Or that at 20L it pushes 10,000cd. I could be wrong but I think the specs are greatly exaggerated by the manufacturer. I've never heard of a 200L light with that kinda throw potential. Even the TN31, which is one of the top throwers has 1150 lumens but with only 75,000cd.
    Its either over stated, or, aspherical.



    I looked, it looks like an ordinary spot light from wally world, etc, but with an anemic LED. (Not an aspheric or a flashlight)

    So its just over stated, or, the dot of light is so small as to be be useless.

    Last edited by TEEJ; 01-04-2013 at 03:39 PM.

  9. #9

    Default Re: Some questions

    Yes, the beam is verry narrow, but very very bright.

    And i think, it reaches 600 metres with ease, when i shine towards a farmerhouse in the dark, at 500 metres distance, it lits up very well!

    But the lightspot is indeed very narrow and small, but lucky, very bright.

    I can spot sheeps and cows at 400 metres distance at the highest setting of 210 lumens.

    Im very very happy with this light.

    I soon will make some beamshots, and place it here on this forum.

    This is the light.


    See Rule #3 Do not Hot Link images. Please host on an image site, Imageshack or similar and repost – Thanks Norm
    Last edited by Norm; 01-08-2013 at 01:18 PM.

  10. #10
    Flashaholic* PhotonBoy's Avatar
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    Default Re: Some questions

    Found on this page:

    http://www.maglite.com/flashlight_performance.asp

    Q: What does “Beam Distance” mean exactly?

    A: According to the committee that developed the FL1 Standard, a flashlight’s “Beam Distance” is the maximum distance (in meters) at which it will produce “0.25 lux of light.” That, as the Standard explains, is “approximately the equivalent of the light emitted from the full moon ‘on a clear night in an open field’.” Nobody would say that’s as bright as day, but everybody can agree that the light of the full moon in a clear sky is a useful level of light. You can see by it well enough to find your way around, and you could even read by it if you had to.

  11. #11

    Default Some questions

    Just because you can see the light from 1000 meters does not necessarily mean that it is illuminating objects at that distance.

  12. #12

    Default Re: Some questions

    So ,im really flashaholic,i can tell. Thats why i found this great forum.

    Some last questions,

    1 Is the illuminating bright at a distance of 100 meters ,of a 670 meter beamdistance flashlight?

    2 And at 670 meters, will the illumination then also still be bright?

    3 And at 1000 meters distance, still illumination, or nothing of that?

    4 And when i am at the maximum illumination point of 670 meters, and the light switched back to low setting of 240 meters beam distance, what will happen then at the 670 meters point where i stand? Will the illumination then still be there, or is it gone?

    I will soon test this things for fun, with a good friend, who is also a flashaholic ,like i am.

    Thank you all, for your nice help.

    Remco

  13. #13

    Default Re: Some questions

    Nobody?

    Can somebody help me with this last questions?

    Thank you all.

    Remco

  14. #14

    Default Re: Some questions

    please help me with my last questions.

    See 2 posts above.

    Thanks.

    Remco

  15. #15

    Default Re: Some questions

    Why no reactions??????????????????????????/


    Whats this!!!!


    What kind of unpolite persons here.

    I really hate this world it is today!

    No kindness, no friendl;y people anymore.

    Pleae ban me , in not post anymore post /message here.

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