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How Does a Rangefinder Work: Basics for Beginners

How Does a Rangefinder Work
Written by Robert Stevens

If you’re anyone like a passionate archer, or a vigilant hunter, or a hard-working golfer, or even a friendly birdwatcher, a rangefinder should be one of your important possessions. If you don’t own one already, you’re going to get one sooner or later. Either way, some basics of rangefinders will help you, especially in different outdoor surroundings where the exact range (distance) to your target is what determines whether or not your mission will be fulfilled. Today, I’m about to explain one very explicit topic, “how does a rangefinder work?” By the time you’re done with the reading, you’ll learn what really matters when a rangefinder is in question.

Before the conceptualization of laser rangefinders, optical rangefinders were all we had. The accuracy of those devices varied with the changes in distances. Consequently, we had to suffer from inconsistent readings at times. Most of those devices were bulky and heavy making it clear that outdoorsmen should have something more compact and technically capable in terms of range-finding. Thanks to people who brought laser range-finders and contributed to the way we enjoy accuracy nowadays!

The best thing about these modern gadgets is that you won’t miss anything, from performance to portability. Some high-end models may perform better than other makes and models, though. Let’s get right into the depth of the mechanism rangefinders these days rely on. I’ll also talk about some types and how they function differently to suit the purposes they are manufactured to serve.

How Does a Rangefinder Work?

Rangefinder Work

Understanding Technologies of Rangefinders

As in every other outdoor avenue, technology has put its marks of advancement and sophistication on optics. Different opinions might come, but I think the last two decades were the ripe time for people who longed for an ultra-modern range-finding device that will put them at rest giving them the most optimal yardage. We, the community that loves outdoor adventures, have an access to laser rangefinders, the most advanced of all. Let’s learn how these small gadgets work.

1. Laser Rangefinders

Laser rangefinders have pretty simple workaround. It shoots laser beam (typically at a speed as high as that of light) from the emitter to initiate its function.

How Does It Work?

While many experts would tell you that a laser rangefinder works in the same principle as an autofocus camera does, I won’t divert your attention toward that complicated world of electron-optics technology.

An autofocus camera projects an infrared laser beam (technically invisible) to the target. Soon, the beam hits that target and reflects back right to the camera. A sensor preinstalled in the camera detects that returning reflection.

Then, a computer chip starts working by translating the time required by the beam to be back to the target and into the distance to the target. That distance should be calculated, and once the calculation is complete; the next mechanism initiates. An autofocus camera contains a computer chip that signals the camera motors to focus its lens to the calculated distance.

Did you understand the above technology? Laser rangefinders depend on this principle with the exception that the camera motors and lenses aren’t available.

In this case, an infrared laser beam (invisible) from your device hits your desired subject and reflects right back to the device. A computer chip which is already available inside your unit translates the time required by the laser beam to come back into a distance. Then, you see the ranges on the display. Due to the speedy operation (like that of light), you need not wait longer than a few seconds to get the reading which is oftentimes accurate and reliable enough to satisfy your demands.

Among the available technologies for hunting and birdwatching, this one stands firmly with its accuracy and reliability. Most units using this technology give accuracy of +/-1 yard, which should be enough for anyone undertaking a very detailed hunting adventure or a leisurely event (watching birds, animals, and wandering about the thick forests). Even, manufacturers have made it possible for the most demanding buyers to want an accuracy of just a few inches by bringing in some rangefinders.

2. Optical Rangefinders

Golfers and hunters are the typical users of optical rangefinders. Optical rangefinders are the cheapest of all other types.

optical rangefinder

How It Works?

Optical rangefinders consist of monocular devices including built-in scales. There is a pre-loaded conversion chart to provide the list or graph for distance reading. The eyepiece of the unit measures the pin height.

There are two lenses at the opposite ends of the rangefinders that focus on the object. The focusing knob creates overlays of the images on each other. The knob marks with the scale that converts the reading in the distance which isn’t confusing. Hold your device with caution; otherwise, accuracy might get limited.

3. Sonar Rangefinder

Sonar uses sound pulse and time for the sound waves and gets back from the target at the speed of sound. Later, it reads and displays the distance to a target. However, these devices aren’t as popular as their laser competitors.

4. Radar Technology

RADAR means Radio Detection and Ranging. It can releases the beam over a large area. It mainly uses in determining the distance and speed of large objects. RADAR sends out a pulse of laser light beam with a pulse of the radio signal to detect the target. Radio waves usually travel as the speed of light to enable the RADAR to read the time and travel of the laser light to the objects.

5. Lidar Technology

LIDAR mainly works similarly as RADAR. It is much expensive than RADAR and it provides detection of smaller and tiny objects. The way LIDAR works is much the same as the RADAR does. However, it works on a much larger scale than RADAR. It releases the light pulses towards widespread objects unlike radio waves or sound pulse. These rangefinders aren’t as efficient as the laser and optical units.

Understanding Rangefinders by Their Purposes

There are various purposes you can use the rangefinders for. You can use rangefinders when hunting or playing golf to improve the skill of getting the proper target. The different rangefinders serve for different purposes. To know more about the different purposes of rangefinders, read below.

1. Golf Rangefinder

Golf rangefinders help you to count the particular target. The golf rangefinders offer precise measurement ability to give you the actual readings. There are two types of golf rangefinders. They are, GPS and laser.

golf rangefinder

How It Works?

GPS requires you to download the map of the golf course and the other measures the distance of the specific target. GPS technology offers accurate distances even in the green fields. You don’t need to have proper findings to know the readings of GPS rangefinders.

Laser rangefinder system works to have better accuracy than GPS. It can take accurate counting and distance from the device and the target. It also has excellent accuracy to have a higher magnification level.

2. Hunting Rangefinder

Hunting consists of several different things to consider. There are different hunting tactics if you have rifle, bow hunting or shooting purposes.

hunting rangefinder

How It Works?

If you are off to bring a rifle with you for hunting and with long-distance shooting, you may need 7x to 8x magnification to get the expected result. Due to the vagueness in the wild, you may need to have quality rangefinder to go through the hunting.

Bow hunting rangefinders are compact and lightweight with angle compensation. The lightweight feature gives the user a fresh experience with being able to store easily and focus on the target.

For shooting competition purposes, there are selected rangefinders that bring supportive features to step up your skills in shooting.

3. Forestry Rangefinder

These rangefinders mainly used in forestry or in the deep forest. Overall size and weight of the model varies in forestry rangefinders.

forestry rangefinder

How It Works?

These rangefinders use the anti-leaf features which enable a user to reach their target with ease. Other features included in this device is, the capability to determine the height of the trees, the volume and getting the distance in between the device and target. There are other forestry rangefinders, such as light and heavy versions where you will get the chance of picking several other models.

4. Photography Rangefinder

Photography rangefinder comes with great features. It lets the user cope with the distance to find the object being shot for precise focus and tool for the better quality of photos.

How It Works?

The different types of the camera which includes focusing device located on the front and it lets users to regulate the distance between the shot-object and the camera to get the desired focus. You can also standardize the wheel and the camera’s focus.

When 2 images get processed in the viewfinder and come out as a single image, the camera establishes the well-defined, precise focus. Later, the photographer then can test the wheel to recognize the range.

The market has several cameras and digital cameras including DSLR which is the main attraction of these days’ photography rangefinders.

5. Ballistic Rangefinders

Here it is another technology to work for the high range shoot. This rangefinder assists you to get the long distant objects. It includes firearm technology, and the other is a laser one.

ballistic rangefinder

How It Works?

When the device detects a target, it shows the readings by emitting light. This device has maximum ranges up to 1500 yards making itself ideal for military projectile release. The army rangefinder had a heavy optical device for measuring the distance. These days, firearm technology has developed, and it is more accurate and is a great advancement to the ballistic rangefinders.

Now, what’s left? I’ve covered the basics without filling too much of the technicality into your head. However, I’ll be happy to inform you further upon any question or suggestions regarding rangefinder or other optics. Happy outing!

New
Bushnell Prime 1800 6X24 Laser Rangefinder | ACTIVSYNC Display Technology | Tripod Ready with Mounting Screw_LP1800AD
  • [BUSHNELL] is a leading Optics manufacturer based in the USA that has been serving the outdoor and wildlife enthusiast for more than 70 years.
  • [ACTIVESYNC] New display technology fluidly morphs from black readout against bright backgrounds to red against dark ones, with infinitely variable tones, so your target stands out in all lighting conditions.
  • [LOW LIGHT PERFORMANCE] 2X brighter for dim conditions, 50% larger objective lens paired with an all-glass optical system bring more light to your eye for a brighter image in dark environments, like heavily wooded courses.
  • [TRIPOD MOUNT] Assures stability for quick target acquisition and ranging.
  • [FAST RANGING] Scan mode updates range 4x per second for fast, reliable ranging across all target distances Great for understanding the distance of elements around your shot paths for archery, rifle hunting or multiple target shooting.

About the author

Robert Stevens

A Seasoned Hunter

It’s been several years that Robert, a retired teacher and a proud dad, has silently been piling up mature bucks down the South. This humble hunter began his hunting journey at quite an early age and since then, he spent countless hours in the woods and learned good lessons in terms of woodsmanship. Along the way, he also made money sharing his skill with his followers and well-wishers.

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