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How does a rangefinder work

how does a rangefinder work

At its simplest a rangefinder works by finding at what distance an object is away from you. The advantages of this are clear. Most archers could judge a reasonable distance by using just their eyesight alone, but eyesight can only get you so far. In order to judge the perfect shot, you need to know exactly how far away the object is.

Having a rangefinder allows you to account for the likes of wind speed and gravity to make sure your arrow lands exactly where you wanted it to land. They have never been more accurate with a few different types on the market. They are great for a multitude of different activities such a sports and photography, and of course, archery.

The process of determining distance is called ranging, hence where the term comes from. They have been around since the 1880’s, but thankfully they have improved since then. Depending on the type that you choose, you can also acquire many other measurements such as wind speed, air pressure and ballistics compensation that can all help you with your shot.

Types of rangefinders

Whilst there are quite a few ways that distance is measured in the modern world, most of these don’t lend themselves to being used with a small handheld device. What that means is that rangefinders for the world of archery generally break down into two separate categories.
Optical rangefinders were the first to come onto the market, as they are simpler and easier to make. The problem with optical rangefinders is that the process can be quite slow. They work by using lenses and mirrors to make a double image, and then the viewer brings these together until they are matched. You then read the dial that you’ve used to bring the images together, and that will tell you the distance to your required object. These are generally cheaper, but due to the time taken their popularity has been far overtaken. They are a throwback to a more manual time and an old school way of doing things, so if you want that experience, then they can be a great choice. In the world of handheld range finding today though, laser is king.

Many people are unaware that laser is actually an acronym, standing for ‘light amplification by stimulated emission of radiation’ which can be quite a mouthful. These are by far now the most commonly used rangefinders for archery and all other forms of individual activities. As shown by the acronym, a laser is a beam of light and it travels as fast as such. This makes laser rangefinders incredibly quick and the reading on your screen will be instantaneous. Considering light travels 186,282 miles in a second, it’s fair to say you won’t be waiting very long for that reading on your meter. That speed is the reason why laser range finders are generally preferred above all others and they now dominate the market.

How does a laser rangefinder work?

The basic principle for a laser rangefinder is a fairly simple one. A beam of light is shot out from the device, and that beam of light is then reflected back into the device, it then measures the time that it took for the beam of light to travel back. As the speed of light is constant, it uses this time to calculate the distance that an object is away.

Whilst the basic idea is very simple, there are a few things to consider when it comes to the laser and how effective it can be. The beam of light is designed to be as narrow as possible, but as light can do, it spreads out over greater distances, so you have to be sure the measurement you are getting is the measurement that you were planning to get. This is called beam divergence, as the beam can be diverted by the atmosphere and other objects.

As it is a beam of light, a reading through glass may be difficult as most of the light passes through, depending on what type of glass it is. As it relies on light being reflected back, if the beam meets a mirror, then this may also throw a reading off. This reliance on reflected light is very rarely a problem, however, as even objects which look as though they are angled away will be able to reflect back some of the light. If you are trying to calculate the distance to a target, or an animal, then the reading will be a very accurate one.

You may think that a device relying on a reflected light would often have interference from the light that we see all around us. Thankfully the device is tuned to only read the wavelength of the light that is fired out. As all different types of light have different wavelengths, only the laser light is measured. As laser light isn’t something we have to deal with in everyday life, this causes no problem for the device.

You would be right in wondering that, if there is beam divergence and the light can pass through some objects and not others, then how can you trust that you are always getting the right reading? Well, it isn’t just one beam of light that is fired out by the device, it is constantly sending out beams to be measured. If it takes some measurements from around the target then it will discount these as the majority of the readings will be coming from the same source, which will be the target that is right in front of you. It uses complex algorithms to decide which distance is that one that you want to read, as that’s the one where the overwhelming majority of the readings will be coming from.

How to pick the right rangefinder for archery

As with any piece of modern technology, there are numerous features which can differ from one device to the next. It can always be difficult to work out which ones are important, and which aren’t. Laser rangefinders contain a lot of advanced technology, but thankfully their price on the market can be very affordable. Finding the right one for you can depend on a lot of things, including your budget. As with any technology item, you won’t be surprised to know that they can range in price from the likes of $15 to thousands. Also with any technology item, you can be wondering how much do I exactly have to spend to get the quality I want? I can be hard when you’re faced with such a huge price range.

In this essence, it’s the same process as any technology that you have bought before. You have to work out exactly what features you need and which you are happy to go without. It could be the case that you just want a simple device for a rough guide on target distance. It could be that the perfect shot is vital to your needs, and therefore a multitude of features will help you achieve that.

You already know what you want to get out of your rangefinder, so make sure that is reflected in how you get one. For example, there are devices out there which are specifically designed for golf. These would not be ideal if you’re going out hunting with a bow and arrow for example. They have their differences, so you need to ensure that not only are you getting a rangefinder to suit your budget, that you’re also getting one that suits your needs. Not spending enough time researching the right rangefinder will leave you frustrated and with a device that is not right for you.

There are quite a few things that an effect the price of a rangefinder, and just settling for one that seems like the right price isn’t always the best thing to do. While you may get a decent one form a well-known brand and be happy with it, it could be better to go with a lesser known brand which has all the features and is the perfect thing you’re looking for. Carefully checking what features you desire with the budget you can afford is the best way to get what you’re looking for.

You also need to consider how and where it is going to be used, and how much time and effort you want to put into reading instructions. If you want to have some fun with the kids and try out some target practice with a great little gadget, you want one that’s easy to use which you give you the information you need immediately. If you want one for hunting then you may be willing to spend time to master a device which is a little more complicated. Whichever your reason, you’ll most likely want a quick reading. This is why the laser rangefinder dominates the market as the old optical rangefinders take a lot longer to use.

Rangefinders aren’t new, and they’ve been around for a long time now. A decade ago you’d probably have had to pay a lot of money to find anything decent, but the truth is these days is that you can pick up an accurate rangefinder for fairly cheap. As with many technology products, they try and dazzle you with gadgets and features, but the simple fact is that most people want one to find out how far something is away from them. All rangefinders do that, and they all do it well.

All products should give you their range of accuracy, and some will be much further than others. You have to bear in mind what you will be using it for and what targets you intend to spot. With archery, it shouldn’t make too much difference as obviously there is only a certain distance that you can shoot an arrow. All rangefinders should give you a solid reading for such a short distance. A rangefinder will generally give you the distance it can see in perfect conditions, and also a standard accuracy for various targets.

If you are on a hunting trip, or just target practice, it’s likely that you will be out on your feet for long periods. You want to pay attention to how big the device is and how easy it is to carry. Also see whether it comes with any carriers for easy movement. Again, this is where the use for archery can be an advantage as you will only require ranging at short distances compared to someone who wants to use one for a rifle. You want to make sure it easily fits in one hand.
Finally, if you wear glasses then you need to look for a feature called eye relief which will let you see into the rangefinder when you’re still wearing your glasses. It is recommended that you allow for a minimum of 15mm to enable you to see through the device and still lock on accurately to your target.

Make that perfect shot

Archers know how crucial just 10 yards can be when it comes to firing an arrow, and sometimes it can be hard for the eye to pick up such targets easily. Even if you’re firing at a target, a rangefinder can be a very quick way to ensure that you have the right distance.

It is important to find the right one, however, as there are many options on the market. Thankfully for archery, you are able to look at the cheaper end of the scale. A lot of rangefinders are used for a few hundred yards, or maybe even a couple of thousand. With archery, it will more than likely be under 100 yards, and all rangefinders can cover this. If you think you may use it for other reasons as well, then you can look into a more expensive device. They are generally simple and easy to use and are a super quick way to make sure that you’re going to deliver the perfect shot.

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