Laser Rangefinder 101: How Do Laser Rangefinders Work?

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Laser Rangefinder 101

Not too long ago, laser rangefinders were expensive gadgets that most people didn't know much about, and that's what kept them the best kept secret.

Perhaps that elusive elk could've been yours or that par could have been made. Everyone has had a rueful moment like that.

I'd guess it probably still stings a bit to think of that misplaced shot. And to rub it in a little more, you probably could've made the shot or the par if you had something as tech-savvy as an optical rangefinder for that moment you needed it the most.

Thanks to advancements in technology and the ever-increasing affordability of gadgets, laser rangefinders have quickly found their place in the sports optics realm. With well-known, trusted, and world-class optics brands putting their stamp on the measuring-savvy units, it's no wonder that more and more consumers are getting their hands on them.

Get ready to extend and expand your world of vision, make every par, and never miss a shot.

What is a Laser Rangefinder?

Ah, yes. The $64,000 question. Back in the old days, they were the sight-seeing things we call eyes. Sight, depth perception, and excellently honed distance guesstimating skills were all used by the old-timers to make that well placed shot and bring on home the bacon. But, there was always the chance of human error, and that guess could've cost you your dinner.

Perhaps 10 years ago only two people out of 10 could tell you what a rangefinder is. Today, if you're enthusiastic about rifle hunting, target shooting, archery, tactical training, or even if you're just fanatic about using gadgets for military use, then you are the very person that needs to know what a digital rangefinder is if you don't already.

They're so user-friendly, convenient, and affordable that there's really no excuse you should be without one.

The most basic and yet primary function of these optics perform is distance measurement. That is reason enough for a lot of people to buy one. It might even be reason enough for you.

However, because we live in the 21st century, basic functions are often only the gateway to better features to come. But, before we get into that, what's the science behind how these devices work?

How do Laser Rangefinders Work?

Why would you need to know this? Isn't it enough to just push the button? Although you may want it to be that easy, you'll actually get more effective use out of your device if you know how to use it because you know how it works.

You might have heard of skeptics griping on about how temperamental they can be. Inconsistent readings, not reaching maximum yard range, and poor accuracy are all common complaints you might hear about them.

But, did it ever occur to you that rangefinder error might be because of the user? Let me explain to you the science of how these units work in layman's terms.

A rangefinder uses a laser diode to reflect off a target and back to the unit. The laser diode pulses out wavelength light that's invisible to the human eye.

Fun fact: Visible wavelength light is between 400-700 nanometers (nm). You can expect various quality units to emit wavelength light upwards of 900 nm.

With a push of a button a laser beam emits from the device to a reflective target. Depending on the amount of ambient light available and the target's reflectivity, shape, size, density, and color will affect how much light is reflected back to the rangefinder.

The unit measures how much time it takes for this process to happen and converts it to display distance. All of that sounds like so much work, yet all of this happens within nanoseconds. Pretty impressive right?

How Laser Rangefinders Work

But, don't get confused about what makes the best optical device. A huge part that makes up a high-quality optic is not in the quality of the laser diode being emitted from the unit. It's actually all about the unit's electronic sensitivity to detect and receive reflected light.

If this ability is top-notch, then all other added features will function perfectly. Then comes the perks of having quality lens and rugged construction.

So, where's the human error part?

A lot of the reason inconsistencies occur is because of the user. Many people don't understand that a laser beam actually increases in size the further your ranging distance. For example, a laser diode measured in mils (an angular measurement) that is approximately two mils wide and four mils high would expand to be about two yards wide and four yards high at 1000 yards.

To get the most accurate reading, the target size should be indicative to the beam size for the distance. To avoid errors, here's the long story made short: ranging small sized targets is best for close range distances and larger targets are best to range for longer distances.

Not understanding the way a laser beam changes in size can cause your device to not generate a reading, fail target acquisition, or range an unintended target instead.

Do I have even better advice? You betcha. Because of the way they work, you need to buy a rangefinder appropriate for your intended use. Period.

How Can a Rangefinder Up Your Game?

Remember earlier when I said something about missing that buck? That stinging sensation you feel deep down inside should be motivation enough for you to use one. If you have awesome distance estimating skills like that of Iron Man, then these rangefinders are not for you.

If you don't want a repeat of why you're the laughing stock among your golf buddies or your fellow hunters, then you need to get your hands on one ASAP. Even a cheap rangefinder can up your game significantly.

Different types of rangefinding units offer different features that can be beneficial for many reasons. Some of the most popular features are:

  • Pre-loaded golf courses
  • GPS capabilities
  • Bullet drop/holdover compensation
  • Inclinometer for angle compensation
  • Barometer
  • Bow shot clearance

Rangefinders are extremely helpful to help you sight-in scopes, practice for target shooting competitions, train for tactical purposes, improve your golf game, and better your hunt.

Like any other gadget, it exists for your convenience, enjoyment, and sometimes, even your own safety but getting the most out of your rangefinder means buying one that best suits your needs. So before you splash the cash you need to consider what you will be using the device for; Golf or hunting? Rifle or bow? Short or long range shooting?

Only once you have determined how it will be used will you be able to decide which is the best rangefinder to up your game.

Happy ranging!

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