Friday, January 17, 2014

Red Light LED - a Prepper's Friend

A current requirement of any headlight I buy (and I buy quite a few, both for me and for some of my friends) is that they have a red light LED setting. The reasons for this are pretty simple, and I will present three or four, depending on how you count them. 

The first red light doesn't kill night vision.  This is the real reason the military has provided red lenses on their flashlights for more years than I can remember. (I will expose a myth later) The red light, while not ideal for seeing things, is adequate for identifying location and shape of objects, which is the primary purpose of using a light. 

Red LED's are more efficient.  Simply stated, red LED's, to produce the same amount of light, require only about half (maybe less) of the power of white LED's. This is because the white LED's use produce one color of light, and use that light to excite phosphorous to create the rest of the spectrum. 

Combined, the above effects allow for for less than one fourth of the battery drain, and your batteries can be drained further.  The ultimate result is a usable battery life nearly eight times what you would get with white light. This will give you a great deal of leverage to reduce the number of AAA and even AA batteries you need to keep on hand. Even better if you have one of the few LED lanterns that have a red LED setting and use D batteries (D batteries provide a lot more energy for your dollar).

Last but not least.

The last advantage I will cover is red light doesn't attract mosquitoes.  Mosquitoes, and most other insects are attracted to blue light (think: bug zapper).  White light contains blue light, so mosquitoes are attracted to it. The yellow porch lights don't give off much blue light, so bugs pretty much ignore them (as an aside, I once painted a CFL half yellow and half red, and the result was a little light that gave nearly normal color vision but didn't attract insects and didn't blind people)

Now, on to the myth.

As with anything the Army does, some mythology grows up around it. What red light doesn't do is make you unseen by others. Think about it. Towers have red lights on them so they can be seen by aircraft.  In fact red light can be seen a long ways away.  Blue light is harder to see at a long distance, but in fact, any light can be seen much further than the average person would expect. And I don't recommend blue light because of it's attraction to mosquitoes.  

No comments: