If I remember correctly one of the major news channels had a terrorism expert on their morning show. He recommended carrying a flashlight with a red beam because it helps you see through the smoke better. Is this true or just another "expert's" opinion. I will probably choose something I can wear around my neck like a photon II or Arc AAA.
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Are red led flashlights the best for smoke
- Thread starter Marc123
- Start date
- Joined
- Apr 7, 2002
- Messages
- 2,167
mmmmm.....I don't think a red light will help. A bright Krypton bulb will help get through light smoke but,in my experience as a firefighter, "house fire" type smoke is completely impenetrable.
You could start saving to buy a thermal image camera! I recommend the ISG Talisman. An incredible bit of kit.. (but a bit heavy to hang around your neck like an Arc AAA!!!)
You could start saving to buy a thermal image camera! I recommend the ISG Talisman. An incredible bit of kit.. (but a bit heavy to hang around your neck like an Arc AAA!!!)
- Joined
- Sep 1, 2002
- Messages
- 1,245
I thought that was amber?
- Joined
- Mar 2, 2000
- Messages
- 1,526
I got to agree with my brother from across the sea!In 14 years and many many lights,including "smoke cutter"ones I can say this,although I carry 2 lights they're mostly off while fighting the fire.I have never found a light that can let you see though smoke,most just make it worse,like driving at night in a heavy snow with highbeams on.
Another thing,if red is good for smoke how come there are NO red bulbed lights made for fireman?
Another thing,if red is good for smoke how come there are NO red bulbed lights made for fireman?
Fog lights are generally yellow for a reason. Red would be better in some ways, but most people can not see red illuminated objects as well as yellow illumination. Also, it would look like tail lights on both ends and cause confusion on the road.
First, the color spectrum. The spectrum is continuous, not just discrete named colors. Individual colors are achieved with LEDs, lasers or filters that block the other colors. Or yellow from sodium vapor lamps. This is the cheapest monochromatic (single color) light.
infrared - "below" visible light. too long wavelength, low frequency for our eyes to see.
red - takes more light power to see the same perceived intensity than white or "middle" colors.
amber
yellow
green - Eyes are most sensitive to greenish.
blue
violet - Again, our eyes are much less sensitive and require more light power to see same perceived intensity.
ultraviolet - "above" visible light. Too short wavelength, high frequency for our eyes.
White light is a mixture of some or all of these. The proper combination of 2 or 3 will look white. If not, the "white" portions of this screen, made up of only 3 colors, would not be "white".
The higher frequency/shorter wavelength light refracts more in water droplets like fog and rain. The longer wavelengths/lower frequency light colors will refract less. If a blue light and red light of equal perceived intensity and dimension are viewed through a fog, the blue light will be dimmer and rather larger. It may not even be possible to pinpoint its position because it is rendered into a big cloud. The yellow and moreso the red light will be the smallest, least spread out. Blue fog lights would in essence curve around and shine in your face in the fog, the red or yellow would shine straighter, illuminate stuff and be reflected back more usably towards you.
White light will have its component colors separated by refraction, like a rainbow or prism, because of this difference in refraction of the different colors. The blue portions will cloud out, the red portions will shine straighter. This is the concept behind the blue blocker sunglasses that were somewhat popular a while back. By limiting the bandwidth of the light you can focus it more cleanly. White light is terrible in fog.
Smoke is not water droplets, but it might have a major steam or water droplet component, depending on the type of fire. Smoke absorbs light and blockes light, not just bend it every which way. Depending on what type of fire it is, the amount of the light that is refracted, reflected and absorbed will differ. I have no idea what color or combination of colors would be most useful in various kinds of smoke. I would assume that you could take a clear jumbo leaf bag, fill it with differeent types and densities of smoke, shine different lights through it and see if that light illuminated objects on the far side in a useful manner.
Most importantly, the illumination should not be near your eyes. Holding the flashlight right by your face will create a patch of illuminated smoke or fog right in front of your eyes. Whatever light gets through to the "other side" and is reflected back to your eyes will be much dimmer than that reflected off the smoke right in front of you. A chest light or even shin lights would be much more efficient at illuminating the path without creating visual "noise" in your face.
Psalms 119:105 Thy word is a lamp unto my feet, and a light unto my path. Light is dimmed by the square law. If you need to see where you are walking, halving the distance from the light source to the object to be lit will make it 4 times as bright. Natives in various places tie fireflies to their ankles to walk at night. 3 or 4 inches off the path compared to 3 or 4 feet is 1/12 as far. This is almost 150 (12 squared is 144) times as bright light on the path. These calculations do not exactly apply to a flashlight with a focusing reflector that increases the effectual distance to the filament, but it makes a big difference to get the light closer to what is to be lit.
First, the color spectrum. The spectrum is continuous, not just discrete named colors. Individual colors are achieved with LEDs, lasers or filters that block the other colors. Or yellow from sodium vapor lamps. This is the cheapest monochromatic (single color) light.
infrared - "below" visible light. too long wavelength, low frequency for our eyes to see.
red - takes more light power to see the same perceived intensity than white or "middle" colors.
amber
yellow
green - Eyes are most sensitive to greenish.
blue
violet - Again, our eyes are much less sensitive and require more light power to see same perceived intensity.
ultraviolet - "above" visible light. Too short wavelength, high frequency for our eyes.
White light is a mixture of some or all of these. The proper combination of 2 or 3 will look white. If not, the "white" portions of this screen, made up of only 3 colors, would not be "white".
The higher frequency/shorter wavelength light refracts more in water droplets like fog and rain. The longer wavelengths/lower frequency light colors will refract less. If a blue light and red light of equal perceived intensity and dimension are viewed through a fog, the blue light will be dimmer and rather larger. It may not even be possible to pinpoint its position because it is rendered into a big cloud. The yellow and moreso the red light will be the smallest, least spread out. Blue fog lights would in essence curve around and shine in your face in the fog, the red or yellow would shine straighter, illuminate stuff and be reflected back more usably towards you.
White light will have its component colors separated by refraction, like a rainbow or prism, because of this difference in refraction of the different colors. The blue portions will cloud out, the red portions will shine straighter. This is the concept behind the blue blocker sunglasses that were somewhat popular a while back. By limiting the bandwidth of the light you can focus it more cleanly. White light is terrible in fog.
Smoke is not water droplets, but it might have a major steam or water droplet component, depending on the type of fire. Smoke absorbs light and blockes light, not just bend it every which way. Depending on what type of fire it is, the amount of the light that is refracted, reflected and absorbed will differ. I have no idea what color or combination of colors would be most useful in various kinds of smoke. I would assume that you could take a clear jumbo leaf bag, fill it with differeent types and densities of smoke, shine different lights through it and see if that light illuminated objects on the far side in a useful manner.
Most importantly, the illumination should not be near your eyes. Holding the flashlight right by your face will create a patch of illuminated smoke or fog right in front of your eyes. Whatever light gets through to the "other side" and is reflected back to your eyes will be much dimmer than that reflected off the smoke right in front of you. A chest light or even shin lights would be much more efficient at illuminating the path without creating visual "noise" in your face.
Psalms 119:105 Thy word is a lamp unto my feet, and a light unto my path. Light is dimmed by the square law. If you need to see where you are walking, halving the distance from the light source to the object to be lit will make it 4 times as bright. Natives in various places tie fireflies to their ankles to walk at night. 3 or 4 inches off the path compared to 3 or 4 feet is 1/12 as far. This is almost 150 (12 squared is 144) times as bright light on the path. These calculations do not exactly apply to a flashlight with a focusing reflector that increases the effectual distance to the filament, but it makes a big difference to get the light closer to what is to be lit.