A pair of 20×50 binoculars seems to be a high-magnification piece of binoculars with an objective lens diameter of 50mm. You may have one pair or you think about buying one. But the question is, what are 20×50 binoculars good for?
With a pair of 20×50 binoculars, you can watch distant subjects such as ships on the sea, plane spotting, stadium sports, mountains landscape, or even moon and planets watching.
But there is one little trick. 20×50 means that the binoculars have a 20x magnification ratio and with a 50mm objective lens diameter. You won’t be able to watch anything handheld with a pair of binoculars with a magnification of 20x, or even above 10x, no matter how steady your hands may be.
What are 20×50 binoculars good for, in detail.
With a magnification of 20x, you will need for sure a tripod to mount your binoculars on them, due to the shakiness resulted in trying to watch through the 20×50 handheld binoculars otherwise.
A tripod is not expensive, but for sure your pair of binoculars need to support tripod mounting. A 20×50 or any pair of binoculars above 10-15x magnification should have the option to mount a tripod. But in reality, you have to check this before you buy, or with your binoculars.
An alternative, if you want to buy a pair of 20×50 binoculars or anything with or above 20x zoom, you can have a look at the models with the image stabilisation. This is a technology mostly found on the lenses of some DSLR or Mirrorless cameras, to be able to take better and steadier pictures in low-light situations.
In the case of binoculars, those image stabilisation options, like the ones manufactured by Canon (as Canon 18x50mm Image Stabilisation Binoculars (Amazon Link)) they are pretty expensive, and if you are looking for a good pair of them, you need to have some deep pockets.
Alternatively, there are image stabilisation binoculars, 20×50 around the market (or similar to), cheaper than the ones provided by Canon, but in this case, would be a matter of quality.
The exit pupil of a 20×50
In binoculars, the exit pupil is the bright circle in the centre of each eyepiece, where the light is getting through and goes into your eye pupils.
To understand it better, think about your eye having the pupil open about 2-3mm in good light conditions and up to 7mm in dark or night conditions. If a pair of binoculars have the exit pupil smaller than your eye pupil opening, this would perform worse in low-light scenarios.
As an instance with the 20x50mm binoculars, those have an exit pupil of 2.5mm and in low light conditions, the human eye pupil is opened up to 7mm. This is largely smaller, therefore, a lot of light is lost in the process and the binoculars will perform badly in low-light conditions.
The exit pupils can be calculated by dividing the objective lens diameter with the magnification (e.g. 20×50, you divide 50/20 and the exit pupil is 2.5mm)
What are the 20×50 binoculars good for watching?
Let’s have a little game to better understand the role of 20×50 binoculars and some basic scenarios where you can use with a rating.
Using 20×50 binoculars in Astronomy
If you want to use a pair of 20×50 binoculars in Astronomy, I can say that this is not a good choice, because of the exit pupil being of 2.5mm, at least not for deep-sky watching.
You can still see the beauty of the moon and the crates with shadows under this magnification, the Jupiter and it’s 4 main moons and even Saturn with the rings on its peak.
When observing deep-sky objects or better said, when stargazing, zoom or magnification ratio is playing a secondary role, the main role has the amount of light your binoculars or telescope can capture. Those deep-sky objects are far, indeed, but more, they are very dull.
For this reason, the 50mm objective lens diameter combined with a 2.5mm exit pupil, those are the very negative sides of making most any pair of 20×50 binoculars good for astronomy.
For anything else related to astronomical observation, I would recommend buying something different than a 20×50 pair of binoculars.
In this case, I would give a rating of 4 out of 10 for use for astronomical observations.
Using 20x50mm for birdwatching or nature observing.
If you want to buy a pair of 20x50mm for birdwatching, wildlife or nature observing, you have to take two factors into consideration: portability and handheld observation.
None of the above factors would push the 20×50 binoculars to be the favourite choice of any birdwatcher or nature observer.
In fact, what you will need here is a small, portable pair of binoculars with a maximum magnification of 10x for handheld observation, weatherproof and waterproof.
This does not mean that you will not be able to observe birds, wildlife or nature with this pair of binoculars. You can do it very well if you do not mind the extra weight you carry with you and the need for a tripod to be able to have a great experience in this case.
But do you remember that earlier we talked about the exit pupil of 2.5mm for this pair of binoculars? Well, take this into consideration, because if you are doing observations at dawn, dusk, in a forest or any lower light condition, you will not have that great experience because your image will be contrastless.
For bird watching or nature observation, I would give a rating of 6 out of 10 (without image stabilisation)
Using 20x50mm for plane spotting.
When we are talking about plane spotting we focus on spotting and watching flying airplanes on the sky rather than airshows.
This pair of binoculars is a very good choice when related to plane spotting, due to the high magnification and not so much low light conditions required.
Same as in the other scenarios, it is the best practice to use those in a combination with a portable, small but good tripod.
8 out of 10 for plane spotting
20x50mm and stadium sports.
The stadium sports like football falls under a good category of where a 20×50 pair of binoculars can be used, but it would be a struggle due to the improbability to use a tripod for stability, therefore, it is a good choice to use a 20×50 as long as it has image stabilisation (or similar magnification with IS)
When your seat is somewhere at the back of the stadium, you need a pair of binoculars to be able to follow players directly on the field. A 10x42mm would be a better choice due to size, weight, portability, and the possibility to use it without the need of a tripod
4 out of 10 without image stabilisation, a 9 out of 10 with image stabilisation
Using a 20×50 pair of binoculars for landscape observation & distant subjects or elements.
Not differently from the above categories, 20×50 binoculars would work well for landscape observations and distant elements, as long as you have a tripod for stability and light conditions are favourable.
- But let’s focus a bit on landscape observation, shall we?
In beautiful areas with rich landscape scenarios such as mountains, hills, lakes and so on, using 20×50 pair of binoculars for those types of observations would work flawlessly as long as, of course, you have a tripod to mount it on.
I remember a decade back when I got my hands on a classic 20x50mm (cannot remember the manufacturer) near my home town back in my country, I could observe and explore the large chain of mountains visible from a nearby hill.
The experience was stunning, and although I had not a tripod to mount the binoculars on, I had a fence to lean on the binoculars and create a bit of stabilisation. I also remember the moon rising in the evening over a ridge, seen through those binoculars.
My experience in having those observations leaved a vivid memory in my mind, and after so many years, I still want to give a 10 out of 10 due to the unique occurrence you can have.
- RQ1: What alternative of a 20×50 pair of binoculars can you recommend?
The negative side of a 20×50 would be the exit pupil and underperforming in the low light situation. I would recommend a pair of 20x80mm from Skymaster, for a better experience in low light and astronomical observation
- RQ2: Should I focus on buying a pair of binoculars with 20x magnification or something different?
20x magnification on a pair of binoculars is not a bad choice for many scenarios where you may be able to use. But if you want to carry a small, portable pair of binoculars and perform handheld observation, I would recommend a 10x. For the moon and planetary observations, I would go for a 25x+ for a better experience.
- RQ3: Does it worth investing in an image stabilisation pair of binoculars with a magnification of 20x?
If you have the money and wish to invest into a good pair of binoculars rather than have a bad experience with any cheap ones, YES, I would strongly recommend aiming for an image stabilisation pair of binoculars at 20x+ magnification for the absolutely unique experience of doing handheld observations on high magnification.
Nonetheless, if you are still unsure about if you would go for a 20×50, think about what do you need for and where can you use it. If you need something small and portable, I would recommend going for something similar to 10×42 from Nikon. I own one and I am stunned by the performance and resolution of the binoculars.
But if you wish to perform astronomical observations, a 20×80 or 25×100 would be a good choice to get started.
One way or another, still, a 20×50 pair of binoculars can have a good and positive role in creating a unique experience for observers, like myself after a decade I got my hand on that piece of 20×50.
Stay tuned folks and follow our blog for more binoculars posts. Have a quick look at “what can you watch through binoculars” for more in-detail observations.
Thank you and take care!.