Cutting Through The Fog

[Youfoundnemo]

Why is it that incans seem to "cut" through rain and fog better than LEDs do, is it because incans have a broader spectrum or something else.....do warm tint leds cut through rain well?

 

[LukeA]

Beam pattern is more important.

 

[asdalton]

Why is it that incans seem to "cut" through rain and fog better than LEDs do, is it because incans have a broader spectrum or something else.....do warm tint leds cut through rain well?

A lot of the claims regarding this are anecdotal ... you really need to have a head-to-head test of comparable lights, along with a standard by which to judge performance.

You are sure to hear some incorrect explanations for the alleged difference, such as Rayleigh scattering.

That being said, beams with wide spill tend to reflect more light into the viewer's eyes than beams with a tight hotspot and weaker spill. Many LED beams fall into the former category. The combination of incandescent + reflector gives a predictable beam pattern with an intense hotspot (good lighting of the target) and relatively weak sidespill (less light bouncing back into your eyes).

 

[Guy's Dropper]

Incandescent light cuts through rain and fog better than led light, whether it is focused or not. LED light seems to reflect off of everything, even dust.

 

[tarponbill]

Incandescent light cuts through rain and fog better than led light, whether it is focused or not. LED light seems to reflect off of everything, even dust.

That's been my experience so far. The few LED lights I have are not good in hurricane weather. The Maxfire LX incandescent seems to work best overall. The 2C CREE Task Force with it's tight beam did best for LED style. Not sure why, but reflection and backscatter off the blowing rain was very bad, and limited visibility.

I tried them all together recently, same conditions. My test was not that exact, I live on a saltwater bay and it gets really dark when the hurricanes come. It rains sideways, the blowing rain also picks up a lot of salt from the water.

I was quite disappointed in the LED lights performance in the blowing rain.

 

[PhantomPhoton]

Honestly I can't see much difference between LED, incan, and HID. Beam profile and position of the light source relative to my eyes seem to affect visibility/ penetration much more. It rains up here sometimes too...

 

[firefly99]

Why is it that incans seem to "cut" through rain and fog better than LEDs do, is it because incans have a broader spectrum or something else.....do warm tint leds cut through rain well?

Go out in the rain and fog, see if incan or LED works for you.

 

[ScubaSnyder]

Certain filters assist with penetrating fog, I know orange around 570-620nm approx. works pretty well, yellow also works, around 570-580nm area. Its hard to deal with fog as water is very refractive in terms of artificial light.

 

[sORe-EyEz]

yes i agree amber/warming filters can assist in penetrating fog. i use (in photographic talk) 81D filters for my Peli's. but it also reduces the output by abit.... :thinking:

 

[GreySave]

I have to agree with the beam type being more important than light source. In a real world test my best light in fog is a TIROS version Inova XO3. It easily trumped a number of incans, including my A2 and Wolf-Eyes products. It may not have been the best at color rendition, but as far as cutting through the fog there was no comparison.

 

[bexteck]

My fire dept just bought some new Streamlight Survivor LED lights and I was issued one. I am wondering just how well it will cut through smoke. The light is also available in an incandescent which most of the firefighters have. Unfortunately (fortunately actually) we don't get enough fires to have many chances to try them out and see.

 

[saabluster]

Beam profile does affect penetration. The more concentrated you make the beam the less likely you are to be looking through the air space where the beam moves through which would be reflecting light back at you. The reason some people think their LEDs penetrate better is due to the fact that there are more LED lights that have the collimated beam pattern without the spill(optics) which can wash out your vision of the object you are trying to illuminate. Give the incan the same beam as the LED and it will win every time. Granted that is not nessasarily an easy or practical thing to do.

 

[Blindasabat]

Well said Saabluster. I have compared my A2 with many cool LEDs (no warm/neutral at the time, but warmer tint Luxeon V1) in seemingly clear conditions that were just humid and the LEDs all reflected back on the otherwise invisible water in teh air. The A2 cut through the best by far without blinding me with reflected back light. Don't judge a visible 'lightsaber' of light as brightness. You DON'T want that. Hold the lights pointing downrange and see what the TARGET looks like. Can you see it or is the beam reflecting back actually making your eyes adjust to that reflected light so the target loos more dim?
In the old days fog lights were actually made to work in fog, not just look stupid on people's cars and blind pedestrians and oncoming traffic (they should be outlawed for that). They were Yellow or Amber to cut through fog because those wavelengths worked best. Most LEDs (cool tint ones) don't have that, but incans do.

I really think beam characteristic has less to do with it than wavelengths of output.

 

[asdalton]

Two points that cannot be repeated often enough:

1) Adding a colored filter to a beam cannot help it penetrate fog or smoke better. A filter merely excludes some photons from the beam. The remaining photons continue on in the same manner that they would have without a filter.

2) Wavelength-dependent scattering in the atmosphere occurs when the particles are much smaller than the wavelength of light. This means air molecules, or hydrocarbon haze on the large end. Also, the distances involved are many kilometers. It is not applicable to fog or rain particles, and not applicable to the distances relevant for flashlights.

 

[Blindasabat]

Like dalton said...

A lot of the claims regarding this are anecdotal ... you really need to have a head-to-head test of comparable lights, along with a standard by which to judge performance.

You are sure to hear some incorrect explanations for the alleged difference, such as Rayleigh scattering.

...or atmospheric scattering. Try them yourself and see.