Hey guys. I figure this is off topic enough…but I got to thinking, now that I have…seen the light and started learning about lights and what not. What is the best way to beat fog…or snow for that matter. Up here in Saskatchewan it can get crazy foggy and snowy in winter. What is the best way to beat this?
Yellow-y colors?
Throwy?
Floody?
What?
I would like to be able to soup up my trucks lighting to cut through fog and snow…is it possible? Or is anything just going to get bounced back at you anyways? Nature of the beast?
Cheap dash cam with a big screen and a powerful near IR (Almost all video chips out there can see far farther into the IR spectrum than we can) light source. Much less scattered by fog.
A K40vn or something like that will not cut through fog.
There is a reason why fog lights on cars does not light up things far ahead. You just light up the fog right in front of you. The spill, and even the beam from the typical thrower will just light up all the fog in front of you in the same way.
Only way to "beat" fog, is to having a small pencil beam, with no spill. Something like an aspheric zoom light with de-domed XP-G2, and warm light. But even then, you will not have a good chance at heavy fog..
The screen is small BTW, AND the onboard IR LED’s are pitiful, see below->>
Regarding the ir light source,+ HP HDSL-4230 ir LEDs+, 75mw straight driven, if using a 555 type timer circuit at 5% duty cycle, the output goes to 375mw. HP data sheet
These are not ’near-infrared” but invisible @ 880nm.
17 deg angle.
My experience; Use “Orange” parking lights for Snow.
The old 94 GMC 1500 p/u worked GREAT will like this at Breckenridge Colorado, w.o headlights!
Range in heavy snowstorm, about 20-30yds
I wish I had the money…but then I would be hanging out on CPF not BLF! hahaha… so basically everything will just bounce back…but infrared will penetrate…interesting. I will keep that in mind I guess
Blue light when it hits fog tends to scatter and reflect back to the source more than red light. Same principal applies to longer wavelength infrared which scatters even less than visible red.
I’ve compared a CW ~6000k p60 and WM ~2700k p60 in foggy conditions and although both probably illuminated the target through the fog in an similar way, the blue beam was much more distracting and more solid in the fog than the warm light. I was expecting more of a penetrative effect from the warm light but it wasn’t too significant beyond the less distracting beam. The less distracting beam is a big benefit in itself though.
Might have to try this again with a real thrower to see if I can get to a point where the blue gets swallowed up completely by the fog but the warmer led still gets through.
And +1 to holding the light low or even high above your head, this makes a big difference. Since that way less light reflects back at you and you’re not looking through the full length of the beam in the fog, lets you see more of the light that gets to the target.
Yellow filters could be a good option to have on hand to add to a CW thrower to improve it’s fog penetration, though as others have mentioned if the fog gets decently heavy nothing but an IR cam will have much of a chance anyway.
This whole fog vs. wavelength scattering thing is totally wrong.It’s a myth.Rayleigh scattering works only when diameter of particles is close to wavelength of wave. Fog particles are way to big for that effect.So any light(infrared,red,green,blue)is equally bad(or good) if you want penetrate through fog,rain etc.
What really helps is holding light very low,close to ground(just like fog lamps on cars).
Lacking the willingness to invade your Southern neighbors’ space, any light that advertises “spill” or “flood” beam will be your enemy. Go for maximum Throw, and keep the torch away from your eye-line. And get used to not seeing much!
Yeah, maybe it's less reflection. All I know is that my warmer tint allows me to see what I want to see, and the bluer tints make me see the light in the fog.
Nevertheless near-IR does penetrate fog a bit better. Most electronic imaging devices have IR filters attached to the sensor because of their sensitivity to it - hence the use of near IR. Even film sees better in the near-IR than we do. Which is quite evident with fog shots. And there are a huge number of particles and there are edge effects.
But it is very important to keep the light source as far from the eyeline as is possible.
My first hobby is photography and there you use a deep red filter for penetrating fog in black and white landscape photography. If you want to increase the effect of fog, you’ll have to use a blue filter. In infrared black and white photography you can make the fog nearly completely disappear.
Well sure but wavelength always plays some role on how light interacts with a medium. Fog and rain particles are just tiny little lenses and shorted (bluer) wavelengths should refract/scatter more than longer ones, Rayleigh scattering doesn’t have to apply for this to have an impact. Just look at a prism or chromatic aberrations through a simple lens. How much this actually matters within the narrow visual spectrum is arguable but it will definitely have some effect, and I would think that a light ray that gets bent more when it hits a fog particle is going to go less far through the fog than another ray that gets bent less hitting the same droplet. But having said that at those scales diffraction starts taking over and that’s a whole other story again…ugh!
But anyway the difference in this regard is probably not that significant. Certainly I’d pick the warm light over cool for fog simply because there is so much less glare from the warm. Whether that’s rayleigh scattering from the air between the droplets or refraction and scattering through the droplets or whatever. Using a blue light in foggy conditions just looks like most of it is coming back and hitting you in the face rather than hitting the target
I’m certain giving the eye a wavelength it’s more comfortable viewing and more able to discern contrast/colours with is going to give the best results at “cutting through the fog”.
and started learning about lights and what not. What is the best way to beat fog…or snow for that matter. Up here in Saskatchewan it can get crazy foggy and snowy in winter. What is the best way to beat this?
