Variable light brightness can be used to blend items with their background and disguise the otherwise obvious silhouette.

This effect of counter-illumination was experimented with as early as 1916 and later during wartime in 1943 for military purposes and became known as Yehudi lights. These lights were mounted on aircraft and also projected onto ship hulls that automatically adjusted light brightness to match the background behind it.

It is interesting to note that this phenomenon also exists in nature in some squids, fish, and shrimp that have bio-illuminecent features, thus diminishing their silhouette.

This causes one to ponder what similar applications could be employed that might help to conceal private property or location to avoid attention or detection. Unlike the use of images or patterns, Yehudi lights would require power for illumination but might be more adaptive in their particular environment.

In recent times I have been focused on perfecting my Bug-Out-Bag (BOB) which is somewhat minimalist in it’s contents. It consists of a small strapped shoulder bag because I also use it when traveling by air and it is small enough to be considered a “personal” item which allows me to take an additional “carry on” item for my clothes, etc.. I carry the ENO in my BOB but as is typical for most hammocks, it has no insulation so it becomes cold on my back-side as I lay in it. On a warm summer day this can be refreshing, but at night you can get hypothermic. For me, an ENO alone would not be a successful overnight option for bivouac. In a regular camping scenario I use an inexpensive fiber-filled sleeping bag that keeps me insulated but there is no room in my small BOB for a sleeping bag so I began to seek alternatives.

My first approach was to use a foam/foil windshield screen which I hoped would provide insulation and heat reflective properties. I lasted until 02:00 o’clock but bailed out because I was too cold. The next time I bought an inexpensive inflatable pool air mattress that enabled me to last until 03:30 o’clock before bailing out due to cold. Next, I had a foil/fabric emergency sleeping bag into which I inserted the inflatable mattress. With this combination I was actually able to sleep pretty much through the night. However the foil/fabric bag has issues with condensation so it gets wet inside.

I shared these results with a friend who encouraged me to avoid taking on added equipment but rather, look at my existing equipment for things that might be used for insulation instead. I realized that I pack a Tyvek-type material for use as a ground cloth and a flecktarn pattern poncho. I decided to create a pad by rolling the ground cloth loosely in order to form air pockets. I laid this inside the hammock to cover my seat up to my neck, then I wrapped my poncho around the hammock from underneath and snapped it together over the top. This configuration allowed me to sleep through the night as well without needing the extra gear that I used previously in my tests.

A disadvantage with this arrangement is that it uses the rain gear for insulation so it’s best used in fair weather, but one advantage is that the flecktarn does blend nicely with the surrounding environment.

So, for now, this looks like a workable solution for my minimalist BOB. If I want to do some serious camping, I can be outfitted properly for more severe environments.

For starters, rip-stop material is really tough stuff and is not prone to tearing and if it should get a hole it will not grow in size. Because of this strength it can be adapted to function beyond it’s original intended use as a garment and into a tent-like structure by using fiberglass knock-down shock-cord rods as an “X-frame” being tied in the center with each end anchored at the corner grommets that are incorporated into the poncho design.

My poncho measures 54″x80″ and provides good coverage when configured as a tent. I am 6′ tall and have found a couple of positions to lay where I can be completely covered and yet stay somewhat comfortable. I can lay on my side in a sitting posture with my legs bent. When I feel a need to stretch my legs I remain on my side and form a “V” with my legs outstretched. While in this position there is plenty of room for my Bug-Out-Bag (B.O.B.) to lay beside me.

Should it happen to be raining, you could trench around the drip-line to divert water or build up a layer of insulation beneath you to keep you warm and comfy while at the same time separate you from the wet ground. If it’s not raining I suppose that body parts that protrude out from under the shelter wouldn’t really matter, but I prefer to be covered completely.

I carry my poncho in my B.O.B. along with an ENO double-sized hammock. I decided to try using the poncho as a rain-fly to cover the hammock. As you might see in the photo, it is slightly under-sized for rain but it could be used in a pinch with the sides held out with guy-lines. At the same time it covers the top opening of the hammock to help keep out bugs.

In either the tent or hammock rain-fly mode the camouflage pattern helps to provide a stealthy approach to camping which in some emergency circumstances could work in your favor unless you want to be highly visible in which case you would want to use a blaze-orange or other bright color to gain attention.

If I decide to upgrade yet another time, it would probably be for a larger size or a different camouflage pattern but I am quite pleased with what this poncho has delivered and look forward to testing it out in the field.

It has been written that Albert Einstein used to take a gentlemen’s handkerchief and make a knot on each corner thus creating an improvised hat that he wore while lingering outside on a hot sunny day. A popular method of tying a bandana is to fold it in half on the bias (between opposite corners) thus creating a triangle then placing this long fold on your forehead with the remaining cloth covering one’s head and tying the outside corners in the back over the remaining corner.

Recently I decided to try a cross between these two methods. I tied a knot on one of the corners which I placed on my forehead while covering my head with the rest of the cloth. Then I took the two adjacent corners on each side and tied them together in the back, thus securing my head covering. This method allows me to have much more use of available cloth that covers my neck from the elements or for added camouflage coverage. The knot in front I tuck behind the brim. The knot seems to create a better contour of the cloth and the bandana seems more stable while I wear it.

Perhaps you have a different way of tying your own bandana. Please leave a comment describing your method.

This is all good if you don’t want to be seen, but what happens in the field when you drop some equipment on the ground? When breaking camp or leaving a blind, will you leave with all of your equipment? To compound this potential hazard, imagine being in an emergency situation, under stress, in a hurry, and in dim light. The best tools to have would stand out from the surroundings. There are now blaze-orange camo patterns that are undetected by color-blind animals that are being produced primarily to keep hunters from being mistaken for game, but I’ve recently seen this applied to a hunting knife which in my opinion is brilliant (in more than one way).

So, consider acquiring emergency and survival tools in bright and contrasting colors so that they can be found fast in a time of critical need.