How many lumens = dangerous?

Having seen the video of what some of the hotwires can do I was wondering. How bright can you get and still have a useable light instead of a battery powered flame thrower?

If you have an infinite amount of energy, you could probably make a bulb that gives off 10000 lumens. But good luck finding the power to do it.

What are you going to use the light for? Navigation in darkness takes only 1 lumen. Reading a map takes 5 lumens. Searching the woods takes about 45 and searching for things at long distances requires as many lumens as possible.

MemphisMagD said:

Having seen the video of what some of the hotwires can do I was wondering. How bright can you get and still have a useable light instead of a battery powered flame thrower?

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My USL is usuable. It can fry eggs, start a camp fire, kill mosquitos, and lite up a path, actually lite it up.

Bill

For Mag hotwires, a ROP high is probably pushing it. IIRC, someone here almost set a $100 bill on fire with a 5761.

Monkiee said:

If you have an infinite amount of energy, you could probably make a bulb that gives off 10000 lumens. But good luck finding the power to do it.

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My top light makes 29,000 Lumens, and I think the world record is about 38,000+ lumens from that 400 watt HID Thor light.

16,000 lumens hurts like a 8*$^& out of the front of my Light force Blitz w/ 400 watt bulb, but I am not blind, yet.

223.7 Lumins, anything over that is pretty dangerous.. (Once the UK government figures out how good LED torches have gotten these days, i'm sure thats about the figure they will ban it at )

dangerous? depends on spot intensity...

what about the 60" WWII carbon arc?

Maybe not just lumens but battery capacity
Some of the hotwires and now LEDs are using big big batterys in series.
One short and pooffff.

I would be more worried with high power incans about leaving them around with loaded batteries. Someone could come and turn it on and leave it, nice way to set the house on fire.

my next project, carbon arc flashlight, lol.

Can't help it but...

0 lumens = dangerous

strinq said:

Can't help it but...

0 lumens = dangerous

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:laughing: That's very true!

It's not lumens that's dangerous, it's watts per square meter, multiplied by the percent absorbance of the object it's pointed at. That determines how hot the object gets.

Example: a three watt green laser doesn't put out many lumens, but it can start fires. I almost bought one on Ebay for that reason.

strinq said:

Can't help it but...

0 lumens = dangerous

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I was just thinking the same thing!!!

i wonder how many lm sun produces, if i'm looking at it from a distance that moon is away from earth, assuming i don't go up in flames.

it depends on what you mean by lumens, our the front lumens? recieving end lumens after losses?

Those with film cameras know, if your shooting pictures near the sun, step up the F stops to something tiny...like 22-32 [if you can, 16 is okay] and set the shutter speed higher than ~1/125 sec. Because if you set it at F5.6, at 1/30 sec and whack the the film by making an exposure directly at the sun you will burn a hole on the cellulose and then some :green:

Say if your eye is fully dilated, and exposed by a light in a neglectable distance and in an environment that cannot readily absorb light in a time frame of a few seconds. I believe even at 30 lumens it would cause considerable physical optic nerve damage

now, if your standing on the home side goal post of your school's football field, wearing a pair of sunglasses suited to watch a solar eclipse. There's a high dew point that night so there's light fog near the surface, BVH just happened to set up his AN/VSS-1 on the base of the guest side goal post and just decided to see if he can lightup the homeside goal post
You might not be able to see a thing, but there wouldn't be much damage to worry about other than not losing your grip until your assistent grabs the ladder for you to come down.

a lethal dose has to consider several aspects...

• Light source: what wavelengths at what intensity
• Transmission distance
• Transmission environment
• Duration of exposure
• How sensitive is your guinea pig :devil:

I can melt plastic bags with my FM 12P/2x18650's/P91...:huh:

Chrontius said:

It's not lumens that's dangerous, it's watts per square meter, multiplied by the percent absorbance of the object it's pointed at. That determines how hot the object gets.

Example: a three watt green laser doesn't put out many lumens, but it can start fires. I almost bought one on Ebay for that reason.

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Exactly

That's why staring at a 5mw laser(only a couple of lumen) is much much more damaging then if you stare at a LED producing 1w of light(over 200 lumen).

alpg88 said:

i wonder how many lm sun produces, if i'm looking at it from a distance that moon is away from earth, assuming i don't go up in flames.

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If you are that close to the sun you died a ways back already getting there. Now you are just a crispy fellow. Even in a space ship with tens of meters of lead shielding to stop the radiation, your craft would be unable to shed the heat fast enough to prevent you from being poached in your space suit.

Think about this - you can easily feel the warmth of the sun on your skin, similar the the warmth you can feel from a powerful flashlight at close range. Now consider that the sun is 92 MILLION miles away, and being filtered through several miles of atmosphere.

I don't have the mad math skill to calculate it, but if you expressed the Sun's output in lumens it would be some meaningless exponent anyhow.

Edit: someone on Wikipedia has the mad math skills: ~3.75×10^28 lm (link)
That's approx 37,500,000,000,000,000,000,000,000,000 lumens