How do Laser rangefinders work?

You may have researched a lot about different rangefinders in your quest to get the best. However, the question is, do you know how laser rangefinders work? Laser rangefinders use laser beams to determine the distance between a rangefinder and the target or object.

They use a high-speed clock to calculate the distance. There are numerous components that make up a laser rangefinder. These include the PP which is Pulse and Precision, Range and Range error, calculation and applications. Below is a detailed analysis of how rangefinders work.

Laser beams

Without laser beams, we do not have laser rangefinders. Laser rangefinders use laser beams to get the distance between a rangefinder and the distant object. The moment you press the measurement button on a rangefinder, the laser beam has to reach the position you are pointing the rangefinder at and bounce back at the rangefinder. A laser beam is made up of a receiver sensor, a super-high-speed clock, speed light and software. All these components work for hand in glove to produce accurate distance. 

The moment the laser beam reflects back, there is a receiver sensor inside the rangefinder that recognizes the beam. A super-high-speed clock is there to measure the time taken by the laser beam to reflect. At the same time, the laser beam has to travel at the speed of light.

Did you know that a laser pulse can be as fast as the speed of light? Yes, it does. That is why you can easily get the distance measurement just by the press of a single button. However, the display does not just give you the distance. It is a combination of a receiver sensor and the speed of light.

How then do we get the distance?

Each and every laser rangefinder has software. The software multiplies the speed of the laser beam using the time it took to bounce back so as to calculate the distance to the target surface. This is how distance calculation is achieved when you are using a laser rangefinder.


As much as laser beams are important, how do we measure or calculate the distance of a target that we cannot see or view? Optics allow you to view your target but good optics give you a bright, crispy, clear image. Optics do have different levels of magnification. The higher the magnification, the more detailed the picture is. When you are using a laser rangefinder of one or two times magnification, chances are very high that you will not have a satisfactory view of the whole surface. The view might be so unclear that you will miss that shot. 

Beam Divergence

You might visualize a laser beam as a straight and tight pointer. The more the distance, the more the laser beam spreads out. It is more of an angular pointer. In this case, the measurement of how to spread apart the beam becomes a concern. The same way you are going to figure that distance is the same way you are going to figure out how the target can be measured. Various obstructions might be a setback in achieving the accurate measurement of your target. Beam divergence is all about focus. You might think that the tighter the laser beam the easier it is. The opposite is true. So how then do we get the correct distance measurement? This is when the software comes in.


The software that runs your rangefinder now decides what to do with all the possible measurements given. You will have different measurements and there should be one specific measurement given. The Software also uses certain criteria to come up with a final measurement. When the software chooses to use the closest cluster, what is considered is the cluster of measurements that are close to the user as the final measurement. 

The rangefinder will then give you a measurement of an object very close to your target. The closest reading may be used but chances are very high that you might have a measurement of the wrong object. It can just pick anything close to you unlike using the closest cluster that gives you a measurement of what is close to the object. The furthest reading is just the opposite of the closest reading. 

When the software decides to use the measurement of the most concentrated cluster, it means that it is paying attention to the most common readings. There is now a need to evaluate almost similar readings. It can also choose the most identical readings as the final measurement. In this regard, the software plays a major role in deciding the most possible measurement which has to be precise. The software is the heart of a laser rangefinder.

Can you control the software? 

Yes, you can but only if your laser rangefinder has the new technology of selecting targeting systems. It has to choose amongst three modes which are the Scan mode, Bullseye and the Brush modes. Unlike the Bullseye, the Brush mode pays attention to background targets, not the smallest and closest target.

Aperture size

Laser rangefinders do have different aperture sizes. All the data processed by the software should be stored in a receiver optic. The bigger the size of the receiver optic, the more data you can capture. 


The standard accuracy of a laser rangefinder ranges on +/-1 yard. Anything above that cannot be really trusted. 

Buyer’s Guide

Since it is so simple just to get a measurement from a rangefinder, why is it important to know how a laser rangefinder works?

A laser rangefinder works better if you understand how it works. You will not be able to utilize its functions and features in full capacity if you do not have an idea of these two. The moment you start acknowledging how a laser rangefinder works is the moment you start evaluating different models as you will be able to analyze how you might get different readings in certain situations. In this case, it helps you choose the perfect rangefinder which perfectly suits your specific needs.

Why is it some laser rangefinders do not reach their maximum range?

Some users quickly say it is a false advertisement. However, that might not be the case. A laser rangefinder can work in its maximum ability under ideal conditions. These conditions include low light, flat surface, a big target and highly reflective surfaces.

There are different laser rangefinders and they have a different range of capacities. As a user, you have to evaluate how each and every laser rangefinder works. You need to ask yourself if a certain rangefinder meets your needs. That is how you get to choose a perfect rangefinder. How each and every laser rangefinder works in terms of speed, accuracy and visibility matter most. The more you get to know and understand that the better. You cannot use a device that you do not know how it functions because if something goes wrong, definitely you will not be aware of the cause.

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