What Does 20×50 Mean on Binoculars? Understanding Magnification and Lens Diameter

While buying a  pair of astronomical binoculars, you would have come across many binoculars with numbers like 10×60, 12×50, 20×50, etc., written on the binoculars’ bodies. So if you are wondering what does 20×50 mean on a binocular, Understanding 20×50 Binoculars, then you, my friend, are at the right place. Here we will discuss not only what these numbers mean but also each nook and cranny of these binoculars, so you will know what you are getting into. 

So without further ado, let’s learn more about binoculars and the numbers embossed on their surface.

Key Highlights

  • 20×50 binoculars offer a high 20x magnification for detailed observations at a distance.
  • The 50mm objective lens diameter ensures ample light gathering, enhancing performance in low-light conditions.
  • Strike a balance between magnification and field of view for versatile applications, suitable for both astronomy and terrestrial observations.
  • Be mindful of the larger size and weight, making them suitable for stationary observations and tripod use.

What are Binoculars? 

A pair of binoculars allows you to see anything from far away through the power of its lenses. This means it helps you see a wider field, which means it helps you spot the object of interest faster and in less time. Many people use binoculars in a wide range of applications. The applications include hunting and fishing, astronomy, sports, etc. 

Binoculars are an essential part of our lives. Many people use them to better view the world around us. The advantage of focusing on distant objects is that it not just helps you see them clearly but also helps you get more details about your surroundings. Binoculars are one of the most versatile and valuable tools for any outdoor enthusiast. 

What Does 20x50 Mean on Binoculars? Understanding Magnification and Lens Diameter

What Does 20×50 Mean on Binoculars?

The first number you see on the binoculars is the magnification, while the second represents the effective objective lens diameter. So 20, in the case of 20×50, represents the magnification which is the number of times the optical gadget enlarges your desired sight of view.

Effective lens diameter or objective lens diameter is the second number written on the binoculars, like 50 in the case of 20×50 binoculars. Now, if you are wondering what the magnification and effective objective lens diameter are, don’t worry, as we will have a detailed discussion about them.

What Does 20x50 Mean on Binoculars? Understanding Magnification and Lens Diameter


The magnification of the binoculars is the degree to which a pair of binoculars brings the world closer to your eyes, which means that while using 20×50 binoculars, you will be able to see the view 20 times magnified as compared to the one seen by the unaided eye. 

But one thing to keep in mind is that the higher the magnification is, the narrower the field of view is. Thus with an optical gadget providing a massive magnification, there are chances that you would miss the bigger picture of the view; therefore, the rule of “the bigger, the better” doesn’t work in the case of magnification. 

Another vital thing to consider is that using a pair of binoculars providing a magnification of 20x often comes with the problem of the image’s shakiness. The use of a tripod is recommended to resolve this issue.

Most specialists agree that the optimum magnification for a pair of binoculars lies somewhere between 7x and 10x, depending on the purpose for which you want to use particular binoculars. For instance, you need a magnification of 10x or higher for astronomy binoculars.

Objective Lens Diameter

Objective lens diameter shows the size of the aperture, which controls the amount of light transmitted; thus, a hefty objective lens like 50 mm displays excellent light-gathering ability. Hence, the larger the lens diameter, the more light it transmits and the brighter the view you would get. 

Moreover, the size of the objective lens also directly impacts color reproduction. Let’s be honest; everyone wants a pair of binoculars that provide bright and sharp imaging from dusk to dawn. It would be best if you considered the option that offers you a large, at least 42 or 50 mm objective lens diameter that can ensure a quality view with true-to-life color from sunrise to sundown.

See also  Understanding What Does 8x42 Mean For Binoculars

An important thing to consider is that the objective lens’s size directly impacts the binoculars’ size and weight. Therefore a pair of binoculars with a large objective lens like 50 mm weighs more than its counterparts.

Exit Pupil

Lastly, there is something that is not written on the body of the binoculars, but it indeed makes a lot of difference in the viewing experience that your binoculars offer. This factor is none other than the exit pupil. The exit pupil is the breadth of the stream of light leaving the eyepiece of the binoculars.

It is a virtual aperture in an optical gadget and a small bright circle that can be seen in the eyepiece’s middle. The exit pupil number is something you should also consider because it tells how much brighter your image would seem to be in low-light conditions. The higher the exit pupil number is, the brighter the image you will get. 

It is calculated by dividing the objective lens’s diameter by the magnification it provides and is usually expressed in millimeters. Now, in the case of 20×50 binoculars, the exit pupil will be 50/20 = 2.5 mm. Now, this 2.5 mm exit pupil is quite average, and no doubt that it does an excellent job in daylight, but when it comes to nighttime, then my friend, there are better choices than 20×50 binoculars.

The best low-light binoculars offer an exit pupil of 5 mm or higher. We can conclude that for daytime view, an exit pupil of 5 mm (or in some cases even smaller but higher than 2 mm) would serve right as the exterior light is enough. At night an exit pupil of 7mm is usually recommended to get a clear and crisp view.

If intetrested You can read more about auto focus binoculars.

How to Choose The Best 20×50 Binoculars?

Binoculars are an excellent tool for the outdoors. They are handy for bird watchers, photographers, and athletes. But the binoculars are so much more than that. They are also a great way to see the world from different perspectives. The best binoculars will have various features like excellent picture quality, crystal-clear images, and optically stabilized systems.

These features make the picture clearer. If we are looking for distant views, these types of binoculars are what we need to have as they provide us with clear pictures. Moreover, the best ones will be chosen from various brands, so you can buy something that fits your needs and budget.

So following are some of the features that you should consider while buying 20×50 binoculars.

Field of View

The field of view accounts for the total area or the horizontal width of the view you can grasp with a pair of binoculars without moving your head.

In the case of the field of view, the wider, the better rule sets in as with a broader field of view, you would be able to spot the thing you want to focus on instantly, and it would ensure that you won’t miss out on any crucial or once in a lifetime moment. A field of view wider than 315 feet at 1000 yards (105m at 1,000 meters / 6.0°) would serve its purpose justly.

Lens Coating

The binocular lens coatings mostly add to the light transmitted through the lens. Hence increases the brightness, saturation, and contrast of images with better color reproduction and color fidelity, where contrast means the difference in luminance between adjacent bright and murky areas. The higher the contrast is, the sharper and more brilliant the imaging is perceived to be.

It would help if you looked for fully multi-coated lenses, as they have several coatings on all air-to-glass surfaces with different refractive indices. The fully multi-coated optics being on the high-end ensures the amount of reflected light to its lowest. At the same time, it considerably increases the optical performance and ensures impressive low-light performance. Last but not least, the fully multi-coated lens also guarantees the absence of any chromatic aberration.

If intetrested You can read more about parts of binoculars.

Eye Relief

So no doubt that with a high magnification like 20x, you have to make a compromise in the eye relief, but that does not mean that it should be wholly forgotten. Eye relief is the optimum distance between your eyes and the eyepiece of the binoculars.

More precisely, it is the distance from the eyepiece lens’s outer surface to the point where the exit pupil is formed. The viewer can only grasp the whole essence of the picture if his eye is within this distance.

Low Light Performance

How many of you would opt for a pair of binoculars that would give you a splendid view in broad daylight but a meager or poor viewing experience in low light? No one, Right? We all want a pair of binoculars that provide bright and sharp imaging from dusk to dawn. So low light performance is something we will consider while explaining what does 20×50 mean on binoculars. 

See also  Understanding What Does 10x42 Mean on Binoculars

Now, as the 20×50 binoculars have a hefty objective lens that offers excellent light-gathering ability, there are other things to look for, like whether or not the 20×50 binoculars have extra-low dispersion (ED) glass, anti-reflective coatings, etc.

Prism Type

Prism serves to invert the otherwise upside-down images so that you can see the view as it is. The binoculars come equipped with either a Porro prism or a Roof prism. A Roof prism is lighter in weight, smaller in size, with more optical precision, and a bit more expensive than the bulky Porro prism, which, on the other hand, offers greater depth perception. 

Durability and Weather Resistance

What’s the point of buying a pair of binoculars that can’t even survive a few falls or can’t handle a drizzle or rain? So durability is a feature you should pay attention to while buying a pair of binoculars. Most binoculars now offer rugged rubber armoring that adds an extra layer of protection for the binoculars and gives them a firm grip. Apart from that, you can only sometimes predict the weather when you are out on the field to watch your favorite sporting event or your favorite artist’s concert.

So you and your optical gadget should always be ready for any capricious change in weather. So you should look at the durability of the model because, frankly speaking, Guys! You are spending your hard-earned money on buying the optical device. Hence your binoculars should provide you with features like waterproofing, fog-resistance, scratch-resistance, dust proofing, etc., so that you won’t have to worry about the view’s haziness in a humid environment or the accidental water splashing on your 20×50 binoculars.


Budget is also an essential factor that drives your binoculars choice. We suggest you go for something other than a cheap option because, in most scenarios, the price of a product reflects the quality and features it offers.

Think of it as a long-term investment because you never know by choosing a cheap product; you might end up spending more on repairs or replacement than investing in a pair of optically precise and substantially useful quality binoculars.

How to Choose The Best Tripod For 20×50 Binoculars?

The first thing you need to do before buying a binocular tripod is to identify what type of binoculars you want to use, as we are going to use the 20×50 binoculars, so this much is sorted. You can move directly to the second step. 

After identifying the binoculars you want to use, look for a tripod that is compatible with it. Choosing the best binocular tripod for your needs is a challenging task. There are many factors to consider when searching for the right one. Some of these factors include: how much weight they can carry and what kind of terrain you will be hiking or backpacking on to see whether or not the tripod is stable enough for that terrain.

Apart from that, you should also consider the tripod’s construction material, whether it is aluminum or carbon fiber, etc. The last thing you will need to do before buying a tripod is deciding whether you want an adjustable height or a fixed height and what the tripod head is like.

What are The Best 20×50 Binoculars?

These days, binoculars come in a huge variety, and it may be confusing to know where to look first to get the ideal pair that meets all your needs. We have gathered the best 20×50 binoculars under one roof to simplify your life and simplify this entire scenario. So let’s read and enjoy it!

Some of the best 20×50 binoculars to satisfy your inner astronomy enthusiast are

  1. Bushnell Powerview Wide Angle 20×50 Binoculars
  2. Celestron – UpClose G2 20×50 Porro Binoculars
  3. Ronhan 20×50 High Power Military Binoculars
  4. Free soldier 20×50 Military Binoculars
  5. UncleHu 20×50 High Power Binoculars
  6. FONSAWA 20×50 HD Professional Waterproof Binoculars
  7. FULLJA 20×50 High Power Binoculars
  8. HELENA 20×50 Binoculars

What are The Uses Of 20×50 Binoculars?

Some of the top uses of 20×50 binoculars are as under


20×50 binoculars are one of the best tools for viewing the sky because they are slightly less expensive and significantly less bulky than a telescope. They are commonly used in astronomy as they provide a wider field of view and can also be used for viewing distant objects. Even low-cost models can enhance the color and shape of stars and planets and provide depth to moon craters and landscapes.

Binoculars are excellent optical devices perfect for viewing celestial or distant terrestrial objects. Binoculars with a magnification of 20x are something to consider the next time you go out stargazing with your loved one. With enormous magnification, binoculars ensure a good view of the moon, stars, or planets.

Landscape Observation and Sightseeing

Using a 20×50 set of binoculars for sightseeing will work beautifully while you enjoy the rich landscape and views like mountains, hills, lakes, and so forth, provided that you have a tripod to mount it on.

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Plane Spotting

Now with 20×50 binoculars, plane spotting is a piece of cake. With this enormous magnification that brings the views 20 times closer to the eyes, you can easily observe the intricate beauty of these flying machines. It would be best if you consider mounting your binoculars on a tripod to make this viewing experience enjoyable and less tiresome.

Which is Better, 10×50 or 20×50 Binoculars?

Whether 10×50 binoculars will serve you right or the 20×50 one depends on an array of factors like the purpose for which you will use them, their optical performance, durability, and your budget.


Now, if you want a pair of binoculars for birdwatching or hunting, we suggest you go for 10×50 binoculars as they offer a wider field of view compared to the 20×50 ones. On the other hand, if you want to observe celestial objects and do stargazing with your loved one, then it will be better to opt for the 20×50 binoculars due to their higher magnification.


Now all of us know that high magnification comes with issues like the shakiness of the images, and there is no doubt that you can resolve them using a good tripod. Still, as we are comparing both models, 20×50 binoculars will have more shakiness problems than 10×50 ones.

Field Of View

We all know that FOV has an inverse relation with magnification. So 10×50 binoculars have the upper hand over their 20×50 binoculars.

Low Light Performance

Now the low light performance generally depends upon the effective objective lens diameter. As both the units have precisely the same objective lens diameter, we will compare them based on the second important factor that affects the low light performance of the binoculars, and that is none other than the exit pupil.

Now the exit pupil of 10×50 binoculars is 5 mm while that of 20×50 is 2.5 mm, giving 10×50 binoculars an upper hand over the 20×50 ones based on low light performance.

So, all in all, if you want a pair of astronomy binoculars, you can settle for 20×50 binoculars. On the other hand, if you want something for hunting or birdwatching, it is better to go for 10×50 ones. So, both binoculars have pros and cons, but 10×50 binoculars are a step ahead of the 20×50 ones owing to their better optical performance.    


At last, the rollercoaster ride of what does 20×50 mean on binoculars has ended. Choosing the right pair of binoculars takes work, especially when the market is swarming with options of different specs and sizes. We have tried our best to simplify the whole thing for you by discussing the numbers and features you should look for before making a purchase. After reading this in-depth analysis, we hope that you can fully understand the concept of what 20×50 means on binoculars.

So what are you waiting for? Buy the best 20×50 binoculars for better astronomical night sky viewing and truly enjoy your outdoors!



Which Binocular Magnification is The Strongest?

The strongest magnification of the world offered by a pair of binoculars is 160x, which means that they bring the world a whopping 160 times closer to the user’s eye. With a 160-fold magnification, Sunagor’s Mega Zoom binoculars are the strongest binoculars that won’t let you down if you’re into wildlife, sailing, plane spotting, or even astronomy.

How to Calculate The Exit Pupil Number?

The exit pupil is a virtual aperture in an optical gadget and a small bright circle that can be seen in the eyepiece’s middle. The higher the exit pupil number is, the brighter the image you will get.

It is calculated by dividing the objective lens’s diameter by the magnification it provides and is usually expressed in millimeters. 

For example, in the case of 10X50 binoculars, the exit pupil will be 50/10 = 5 mm.

Which is Better, 10×42 or 20×50?

For birdwatching, surveillance, or hunting, opt for 10×42 binoculars with a wider field of view. If stargazing is the priority, choose 20×50 binoculars for higher magnification. However, 10×42 binoculars generally offer better stability and low-light performance, making them versatile for general use.

What is Field Of View For 20×50 Binoculars?

The field of view for 20×50 binoculars is typically around 3 to 4 degrees, providing a wide perspective for observing distant objects with 20 times magnification and 50mm objective lens diameter.

What Planets Can You See With 20×50 Binoculars?

With 20×50 binoculars, you can observe the brighter planets such as Venus, Mars, Jupiter, and Saturn. However, details like planetary moons and intricate features may not be as discernible compared to higher-powered telescopes.

How Do You Read Binocular Specs?

To read binocular specs, focus on the numbers separated by “x,” such as 8×42. The first number (8) represents magnification, and the second (42) is the objective lens diameter in millimeters, indicating brightness and field of view.

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