Lumen ?

Daniel_sk

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May 29, 2006
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DM51,
any idea how much runtime can I expect with the 9AX Raider with an EO-9 bulb (maybe compared to the stock bulb), running on two 18500?
Thank you.

EDIT: I just read on the LF website that the runtime should be ~35 minutes.
 
Last edited:

22hornet

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Sep 15, 2006
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Province of Antwerp / Belgium
Hello,

I think you will need two lights as well.
Maybe a Fenix 2AA rebel, like L2T V2.0 or L2D and something with good throw. Consider the Maglite MagCharger. A lot is said about Maglite, but it remains a solid fact that they are very strong and the Magcharger has a throw of 173, which is actually better than the great Surefire 10X on high, which has a throw of 145. The Magcharger has about 250 lumens.

http://www.flashlightreviews.com/features/chart_manu.htm

Kind regards,

Joris
 

fineday

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Jan 25, 2006
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China
Welcome!

For home usage, about 30 lumens is enough, and you need a flood light one.

For outside, im my mind it should be as bright as possible, and a spot light one should be better.
 

Curious_character

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Basicaly it will have to luminate a fox at 100 yard's or so & we have been having problems with thieves lately . To be honest i am finding it all a tad confusing .
Prost
Knowing the number of lumens won't tell you whether it'll illuminate a fox at 100 yards. Lumens is a measure of total light output. If that light is spread into a wide beam, you'll light up a big area, but it won't light things up which are far away. The same number of lumens can be focused into a tight beam which will illuminate things a long way off. Of course, if two lights have the same beam shape, the one producing more lumens will light things up more brightly at the same distance.

Another problem with asking for a particular light output is, as several other folks have mentioned, that manufacturers tend to dream up whatever number they feel would help them sell their lights. They get away with this because total lumen output is difficult to measure, so consumers can't check up on the claims.

What you should be looking for is a light with adequate "throw", which is an indication of how far away it will light up an object with a particular brightness. This turns out to be easy to measure with moderate accuracy, and you'll find many posted measurements here and on flashlight review sites. The brightness of the main beam predictably decreases as the square of the distance, so if you know how bright it is at one distance you'll know how bright it'll be at all others. One lux is a dim light level, but a fox illuminated with one lux will be visible. So to get one lux at 100 yards, you'll need a light which produces 100 * 100 = 10,000 lux at one yard, or about 10,000 lux at one meter, the standard distance used for specification. A light which produces one candle, candlepower, or candela (all the same thing) in some direction has an illuminance of one lux at one meter in that direction, so you need a light producing a beam of at least 10,000 candelas at its brightest point.

There are only a very few readily available LED lights having that bright a main beam -- the most efficient currently available LEDs, when driven at their maximum rated power, will produce that light intensity only when focused into a pretty tight beam. One of those which does is the humble 2 or more C or D cell Mag light with a Mag drop-in LED bulb replacement. (Its main secret is its large reflector for tight focus.) Its light level drops by a factor of about 2 in the first few minutes after turn-on due to heat buildup, but it doesn't drop too much below 10,000. I'm not as familiar with incandescent lights, but I think that quite a few of the lights being recommended don't have that bright a spot. Now that you have a number to work with, you can do a bit of searching to find a suitable light.

c_c
 

Nitro

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Feb 27, 2004
Messages
1,347
Knowing the number of lumens won't tell you whether it'll illuminate a fox at 100 yards. Lumens is a measure of total light output. If that light is spread into a wide beam, you'll light up a big area, but it won't light things up which are far away. The same number of lumens can be focused into a tight beam which will illuminate things a long way off. Of course, if two lights have the same beam shape, the one producing more lumens will light things up more brightly at the same distance.

Another problem with asking for a particular light output is, as several other folks have mentioned, that manufacturers tend to dream up whatever number they feel would help them sell their lights. They get away with this because total lumen output is difficult to measure, so consumers can't check up on the claims.

What you should be looking for is a light with adequate "throw", which is an indication of how far away it will light up an object with a particular brightness. This turns out to be easy to measure with moderate accuracy, and you'll find many posted measurements here and on flashlight review sites. The brightness of the main beam predictably decreases as the square of the distance, so if you know how bright it is at one distance you'll know how bright it'll be at all others. One lux is a dim light level, but a fox illuminated with one lux will be visible. So to get one lux at 100 yards, you'll need a light which produces 100 * 100 = 10,000 lux at one yard, or about 10,000 lux at one meter, the standard distance used for specification. A light which produces one candle, candlepower, or candela (all the same thing) in some direction has an illuminance of one lux at one meter in that direction, so you need a light producing a beam of at least 10,000 candelas at its brightest point.

There are only a very few readily available LED lights having that bright a main beam -- the most efficient currently available LEDs, when driven at their maximum rated power, will produce that light intensity only when focused into a pretty tight beam. One of those which does is the humble 2 or more C or D cell Mag light with a Mag drop-in LED bulb replacement. (Its main secret is its large reflector for tight focus.) Its light level drops by a factor of about 2 in the first few minutes after turn-on due to heat buildup, but it doesn't drop too much below 10,000. I'm not as familiar with incandescent lights, but I think that quite a few of the lights being recommended don't have that bright a spot. Now that you have a number to work with, you can do a bit of searching to find a suitable light.

c_c

Informative post. However, I would add what I said in post #12. The Tiablo A8-Q5 has a Lux of ~20000 at 1 meter, which would have no trouble reaching 100 meters. However because LED's are more BLUE, you'll have trouble seeing a RED Fox.

Therefore I'd go with an Incan. There are a lot of good Incan choices, but you should ask yourself TWO questions first. What size do you want to carry? How long of runtime? Those answers will determine your brightness.

My three favorite 1 hour lights in order of brightness/size are the SL TL-3, [email protected] 2C ROP and 3C 1185. The [email protected] 3C 1185 is VERY bright for its size and will run for ~1 hour on 3 AW LiIon C cells. However it's a MOD which requires you to purchase parts and assemble them.
 

Curious_character

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Informative post. However, I would add what I said in post #12. The Tiablo A8-Q5 has a Lux of ~20000 at 1 meter, which would have no trouble reaching 100 meters. However because LED's are more BLUE, you'll have trouble seeing a RED Fox. . .
That's very interesting. It never occurred to me that it's helpful to use a light of the same color as the object you're looking for. When I use a red LED to look at a map, it makes the white areas of the map look red. Red lines also look red, so they become virtually invisible on the red background. In this case, it's a definite disadvantage to have the color of the light be the same as the lines on the map. I also understand that people looking for blood often use a blue (not red) light, for what I thought was the same reason -- to increase contrast between the blood and the background. So I'm a bit puzzled by the idea that a redder light would actually make a red fox easier rather than more difficult to see. Would you be so kind as to explain how that works, and why it's different than blood stains or red lines on a map?

c_c
 

Nitro

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That's very interesting. It never occurred to me that it's helpful to use a light of the same color as the object you're looking for. When I use a red LED to look at a map, it makes the white areas of the map look red. Red lines also look red, so they become virtually invisible on the red background. In this case, it's a definite disadvantage to have the color of the light be the same as the lines on the map. I also understand that people looking for blood often use a blue (not red) light, for what I thought was the same reason -- to increase contrast between the blood and the background. So I'm a bit puzzled by the idea that a redder light would actually make a red fox easier rather than more difficult to see. Would you be so kind as to explain how that works, and why it's different than blood stains or red lines on a map?

c_c

The color of an object is determined by the colors it reflects and absorbs. A red object reflects red light, but absorbs all other colors. If you shine a light with no red (ie blue, green) on a red object, the object will absorb all the light, and reflect none, appearing black. However if you shine a red light on a red object, it will reflect all the light, and absorb none making it appear bright red.

Now take your map example. You are correct that shinning a red light on white paper will make it appear red. This is because white reflects all colors, and if red is the only color, it will appear red. However that's not the same as looking for a red fox in dark woods. To make my point, try finding a RED line on BLACK paper with a BLUE light. That will be much more difficult. So, if a RED fox is in a DARK background, the only way to see it is to shine a RED light on it.

Granted in the real world all objects reflect some of all colors, just to different degrees. Otherwise you couldn't see black objects. Also we're not talking about pure red or blue lights when we talk about LED's and Incan's, but Incan's would be much better at spotting red foxes in dark woods.
 

Curious_character

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I see. So the important thing is the background -- if it's white, it's best to use a light with a contrasting color, and if black, to use a light with a color closer to that of the object you're looking for.

Foxes aren't too common here, and the few I've seen have been in open fields, which make a pretty light background, rather than in woods. So around here, fox ID might be better done with an LED light. The whole area of identification at long distances at night is one that's new to me, and it's something I'll probably never really know a lot about, since I only very rarely have any occasion to do it. But I'm trying to learn what I can. Thanks for the info.

c_c
 

Nitro

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I see. So the important thing is the background -- if it's white, it's best to use a light with a contrasting color, and if black, to use a light with a color closer to that of the object you're looking for.

Pretty much. If you notice, when you shine the blue (or green) light on the map the map appears blue (green) while the red lines will appear black.

Foxes aren't too common here, and the few I've seen have been in open fields, which make a pretty light background, rather than in woods. So around here, fox ID might be better done with an LED light. The whole area of identification at long distances at night is one that's new to me, and it's something I'll probably never really know a lot about, since I only very rarely have any occasion to do it. But I'm trying to learn what I can. Thanks for the info.

I would say even in open fields Incans would be better. For one, at night everything is darker. Second, the incan will also make the GREEN brighter, giving the RED fox plenty of contrast. You really don't want to make the Red fox (or any animal) appear darker then it already is.

In general Incans are better outdoors, because nature has mostly Red and Green objects, and very little Blue. So the lack of Red light in LED's really put it at a disadvantage. However someday LED manufactures will overcome this and come out with a Full Spectrum LED. I'll be all over them. But until that day comes, I'll continue to use my incans outdoors in nature.
 

lexina

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The color of an object is determined by the colors it reflects and absorbs. A red object reflects red light, but absorbs all other colors. If you shine a light with no red (ie blue, green) on a red object, the object will absorb all the light, and reflect none, appearing black. However if you shine a red light on a red object, it will reflect all the light, and absorb none making it appear bright red.

Now take your map example. You are correct that shinning a red light on white paper will make it appear red. This is because white reflects all colors, and if red is the only color, it will appear red. However that's not the same as looking for a red fox in dark woods. To make my point, try finding a RED line on BLACK paper with a BLUE light. That will be much more difficult. So, if a RED fox is in a DARK background, the only way to see it is to shine a RED light on it.

Granted in the real world all objects reflect some of all colors, just to different degrees. Otherwise you couldn't see black objects. Also we're not talking about pure red or blue lights when we talk about LED's and Incan's, but Incan's would be much better at spotting red foxes in dark woods.

Thanks for the explanation. It makes a lot of sense.
 
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