I originally posted this at another forum but it did not get much traffic so I thought I would share it here.
----------------------------------------------------
The survival literature is replete with the advice that signal mirrors are very effective tools and they should be in everyone's kit. I never disagreed with this advice, and have always had what I thought would be a good mirror in all my kits. A while back I stumbled across the TOPS dog tag mirror (described fully below) and while it seemed like a cool idea, I was not sure how well it would actually work. I decided to test it and get the results on video. It made sense to test the other mirrors I had as well.
My friend Bart worked with me to run the test. Bart and I have done a lot of defense, combatives and survival courses together and he did all the video editing for this mirror test, for which I am very grateful.
Here are the mirrors we tested, in the same order you'll see them on the video:
1.
Rescue Reflectors 2"x3", plastic. I got this over 10 years ago based on Doug's advice. The RR model has a center aiming hole with retroreflective mesh, enabling easy 1-handed aiming.
2. Adventure Medical Kits
Rescue Flash, 2"x3", plastic. The AMK mirror also has a center aiming hole with retroreflective mesh. It is a bit thinner than the RR unit.
3. TOPS Knives
Emergency Signal Mirror, 2-1/8"x1-1/16", hard chromed metal. This is a shiny, chrome plated dog tag with a center aiming hole (no mesh) drilled in the middle. It comes with a rubber silencer or bumper which is easily removed. It is very thin. We tested it both with and without the rubber bumper.
4. Lid from the
BestGlide survival tin, a little under 4-1/2"x3", metal. I had some of these tins laying around and figured it would be good to try it. The lid's inside surface is shiny but by no means polished or mirrored. I suspect that if you did polish it, you'd remove the thin coating that keeps it from rusting. There is no aiming hole.
5. Oval hand mirror, approx. 6"x4", glass. This was in my bathroom at home and I figured I'd give it a try as an example of a mirror you'd cannibalize from a vehicle (side mirror, rearview mirror, etc). There is no aiming hole on it, of course.
Bart and I set up on the fields of a local soccer complex. Conditions were ideal for the mirrors: clear skies, afternoon and the camera was facing roughly north. We used GPS waypoints to establish the camera's distance at approx. 550 yards. We took turns both running the mirrors and running the camera.
There are essentially 2 ways to use a signal mirror: one-handed for the mirror with a mesh aiming hole, and two-handed for the mirror with no aiming hole or a simple drilled aiming hole. Both methods are
well demonstrated here by Doug.
Results
Here is the video. The youtube conversion eats a little of the fine detail but it's pretty darn close to what I remember seeing with the naked eye. The "HQ" option on Youtube gives an improved image.
Here are some general learning points we gleaned from the exercise, followed by notes regarding the specific mirrors we tested:
- For a given material's reflectivity, more surface area = brighter flash.
- For a given reflective surface, the flatter it is the better the flash. If you are improvising a mirror then you should take pains to make it as flat as possible. Otherwise you are scattering your signal light.
- A mirror with no aiming hole is hard to aim well, a mirror with a plain aiming hole is easier to aim but tiring, and a mirror with the built-in retroreflective aiming mesh hole is much easier to aim, not tiring at all and is more accurate. I quickly found the two-handed aiming technique to be tiring after 5-10 minutes of use. In a real situation this would be bad, especially if you were injured in an arm and couldn't do the technique.
- For mirrors that have no aiming device (i.e. tin lid, oval hand mirror), the bigger the mirror the harder it is to aim. This is because the bigger mirror forces your eye further out of the line between the mirror's center and the target. The tin lid was smaller than the hand mirror, and I found it easier to aim. The video shows us getting more consistent flashes (though less bright) with the tin lid than the hand mirror. It was an aiming issue, because when the hand mirror did hit the target, it was extremely bright.
- Prior practice with your gear makes a real difference. It took Bart and I some warmup time before shooting the video to hone our aiming technique. Luckily we brought along some radios so we could give immediate feedback. Using a signal mirror is not rocket surgery but you would be well served to have tried it a couple times before a real situation (sound familiar?). You might get only 1 chance to signal that plane.
- Knowing the details about your gear makes a real difference. The Rescue Flash has a removable plastic film on the shiny side to prevent scratches. It is marked "remove before use" which is great. But I noticed that the view through it's aimer was fuzzier than that on the RR mirror. Sure enough, there was a second, unmarked piece of film on the non-shiny side. Removing it made the aiming picture much clearer.
- When aiming don't try to hold the mirror steadily on target. Sweep the mirror's reflection across the target. It is this on/off flashing that really gets attention.
- When using a mirror with a simple drilled aiming hole it is very important to have the mirror close to your face when aiming it; think "nose to charging handle". You quickly lose sight of your target if the mirror is very far from the face. This may seem ridiculously trivial, but on that sunny day I had glacier glasses and a wide brimmed hat on. Only when I removed them could I get the TOPS dog tag mirror close enough to my face to aim properly.
- It is critical that you keep the mirror from getting scratched. Leave the original plastic film on it until needed. I suggest putting a protective layer on the TOPS dog tag mirror using PDA screen protector material.
Mirror specific notes:
- There is no doubt that a mirror with a retroreflective mesh aiming system is the best way to go. You can easily pinpoint the flash on your target. You can easily aim it with one hand, and it is 95% less tiring than the two handed method. The RR and AMK mirror excelled here and you can see on the video that we got the most flashes with these mirrors.
- The aiming "fireball" produced by the RR mirror was tighter and easier to aim than that on the AMK. It was definitely easier to hit a small target with the RR since it's aiming point had a smaller "MOA" than the AMK mirror.
- The tin lid was surprisingly effective. It goes to show that if all you have is an improvised mirror, don't give up hope because in the right conditions (and with some skill) it can be effective.
- The TOPS dog tag mirror is also surprisingly good, despite the fact that all the other mirrors were at least 2.5 or more times its size. With the naked eye, I felt that the dog tag did best with the bumper removed. On a mirror so small, every square millimeter of reflective area must be put to use. This little unit is a stellar EDC/first-line piece of gear. I have one in my wallet right now.
- The hand mirror had the biggest area and most reflective surface (glass), but was the hardest to aim. A scavenged mirror from a car or lady's handbag can certainly be made to work, but it is a pain.
- Based on overall performance, bulk and weight we recommend that a 2"x3" plastic mirror with aiming mesh is a good way to go. I think the RR mirror performs about 10% better than the AMK, but the AMK is a little thinner and much more widely available. You can't go wrong with either one.
- For lifeboat or other applications where bulk & weight are not such a big deal, a 3"x5" glass mirror with aiming mesh is just about ideal. With multiple mirrors, you can hand them out to each survivor in the party to maximize your chances of being seen.
Remember that signal mirrors can be effective at closer ranges even in wooded areas, as shown in this photo I cribbed off the 'net some time back:
Previous Topic
Index
