Seeing Through Cloudy Stuff

[beezaur]

I was out testing my new A2-red flashlight tonight. I took my regular 2-mile walk through farmland after dark for the occasion. I had my L1 and old 6P too.

As I was crossing a small stream I noticed something really wierd: the L1 (white LED) made the water look really milky. In fact I could barely see the bottom through 8" of water. Yet, the red LEDs of the A2 showed the bottom clearly, as though the water was crystal clear. The difference was striking.

Has anyone given thought to the idea that red light (or some other color) might be a lot better than white for seeing through smoke, haze, murky water, and the like?

Scott

 

[357]

I think part of the reason is white leds often have preference toward the blue spectrum. Blue light seems to reflector off fog more so than say yellow light. I think this might be one of the reason incandescents (yellow to amber tint) pierces fog better than most leds (especially HID tinted leds).

 

[wasBlinded]

Part of the reason I built a TVOJ light engine for my Alephs. Though the bluish tinted LEDs look cool, the warmer ones seem to work better outside and give more natural color rendition. Haven't had a chance to see if the warmer TVOJ will make any significant difference penetrating fog/smoke though.

 

[deranged_coder]

IIRC, lights with longer wavelengths will refract less. Since red light has a longer wavelength than blue light it will pierce through better.

At the building where I work we have a soccer (football to you non-Americans) field nearby so the other evening I went on a short walk to clear my head and took several flashlights with me. I stood on the paved path about 15 meters behind one goal and shone the lights towards the other goal. There was a slight bit of fog at the time and the LED lights refracted back a good portion of light while my incan lights had no trouble cutting through the fog and lighting up the other goal.