Laser Rangefinder

What Is a Laser Rangefinder and How Does It Work?

So, we point these devices at our objective, press the button, and a number appears. We know there's a laser involved in some way, but how exactly do these things work? It turns out that this is an old concept.

The concept is similar to that of sonar and radar.

A laser range finder works similarly to sonar and radar in that you send something out and time how long it takes for it to return to you. With a little math, you can figure out how far away the other item that bounced it back to you is as long as you know how fast the thing you sent out can go.

You send out a sound wave with sonar. Sound travels about a mile in five seconds, much like any youngster who was taught how to tell how far lightning travels. Ships utilize the same idea as in all those WWII movies, blasting out a sound wave and monitoring how long it takes for it to bounce back to establish the depth of the U-boat they're pursuing. The fish finder is a more common application today. To fly and discover prey, bats utilize their own type of sonar.

Radar, which uses radio waves, is essentially the same idea. Of course, those go considerably faster, but the principle remains the same: send out the wave, measure how long it takes to be reflected, then calculate the distance based on that time. Other aspects, such as the reflection's strength and other qualities, can also provide useful information, but that's another topic.

A range finder is similar to sonar and radar; however, it uses light pulses instead of sound waves.

The best rangefinder binoculars work in the same way, except it does the reflecting and measuring with a focussed, coded pulse of light from an eye-safe laser. It, like all light, can be obscured by heavy rain, smoke, a twig, and other obstructions. Better range finders will have logic that allows you to choose whether you want to see the first reflection or disregard it if there are branches in the way, and so on.

The rangefinder fires a laser pulse and counts how long it takes for it to bounce back. All of this happens in a fraction of a second for us, because light travels at about 186,000 miles per second. However, the machine is capable of handling it.

It's used in a wide range of situations.

Laser rangefinders are useful in a variety of situations. Hunting, golf, forestry, industrial uses, surveying, and, of course, the military all make use of them. Back in the day, the M1 Abrams tank I used to ride in had an extremely strong laser range finder that could reach many kilometers.

Any rangefinder you'd buy for everyday usage would be safe for your eyes. What is the name of the unit used on the Abrams tank and other military vehicles? Not at all.

A crucial piece of hunting gear

Knowing how far away your target really is is one of the most crucial components of achieving a safe, ethical, and clean kill while hunting. Using a high-quality hunting range finder is the best method to do so. This piece of gear is quickly becoming as essential as camo clothes. And, with high-quality rangefinders available at moderate rates, there's no excuse not to have one.