I did find the Fenix TK20, which uses a Cree neutral white LED. They advertise the light as being superior for outdoor use, specifically for penetration, use and fog & rain, etc.
I'm not an expert on this but I think Fenix's claim of better penetration is not entirely true. When not considering the solid particles in the air (such as dust), water vapor still plays a very important role. As the wavelength increases, the attenuation coefficient (combined absorption coefficient and scattering coefficient) in the visible spectrum of air indeed decreases, however this value goes up for water. In very humid environment or during the rain, I think we lose more light penetration with neutral white compared to cold white LEDs.
It sounds like you know something about the science of this, but my experience with cool white vs warm or neutral tints in the fog is as fenix claims. Maybe what your saying is true, but our eyes can't perceive it. Cool white light bouncing back from the fog blinds the crap out of me.
It sounds like you know something about the science of this, but my experience with cool white vs warm or neutral tints in the fog is as fenix claims. Maybe what your saying is true, but our eyes can't perceive it. Cool white light bouncing back from the fog blinds the crap out of me.
In very humid environment or during the rain, I think we lose more light penetration with neutral white compared to cold white LEDs./QUOTE]
Not true, as long as you stay above the waterline. Even when it's raining cats and dogs, there is still more air than water around you (or you'd drown), so warm tints are still better than cool tints. The absorbtion of the light in the water plays a very small role in humid air. The scattering of the light is much more important. Blue wavelengths scatter much more than red wavelengths, so the red light (of which the warm tinted LED's have more) penetrates further while the blue light (of which the cool tinted LED's have more) scatters immediately.
In water, however, absorbtion is more important. Cool white reaches the farthest underwater because the red tints are absorbed very fast in water while the more powerful blue tints can reach more distance before being completely absorbed.
So, when you want your light to shine as far as possible, for use above the waterline you need warm tints and below the wawterline you need cool tints.
It sounds like you know something about the science of this, but my experience with cool white vs warm or neutral tints in the fog is as fenix claims. Maybe what your saying is true, but our eyes can't perceive it. Cool white light bouncing back from the fog blinds the crap out of me.
JBorneu said:Not true, as long as you stay above the waterline. Even when it's raining cats and dogs, there is still more air than water around you (or you'd drown), so warm tints are still better than cool tints. The absorbtion of the light in the water plays a very small role in humid air. The scattering of the light is much more important. Blue wavelengths scatter much more than red wavelengths, so the red light (of which the warm tinted LED's have more) penetrates further while the blue light (of which the cool tinted LED's have more) scatters immediately.
In water, however, absorbtion is more important. Cool white reaches the farthest underwater because the red tints are absorbed very fast in water while the more powerful blue tints can reach more distance before being completely absorbed.