10×42 vs 10×50 binoculars – which is better?

10x42 vs 10x50 binoculars

Although there are many binoculars on the market and you want to buy one, you’ve seen two similar models, a 10×42 vs 10×50. Which is better for your type of observation?

10×42 vs 10×50 binoculars. Which is better? The 10×50 binoculars possess an objective lens with a diameter of 50mm which offers better low-light performance at the cost of extra weight, where a 10×42 is more portable, smaller in size binoculars. Both of the binoculars has a solid usage in general observations.

With a small difference between both of the binoculars, they have their own usage and each of them may be used in a specific field of observation with advantages over the other. Please keep reading for more information.

10×42 vs 10×50. The binoculars basics

Now let’s split this up and explain each of the binoculars, shall we?

10×42 binoculars have a magnification of 10x which means you can see any objects 10 times closer than with your bare eyes. A 42mm objective lens diameter means that the front glass element is of 42mm. The exit pupils of the binoculars are of 4.2mm.

The 10×50 binoculars have the same magnification of 10x as the 10×42 but the objective lens diameter is of 50mm. With 8mm larger than the 10×42, these binoculars are able to observe better in low-light environments or during the night. These binoculars have an exit pupil of 5mm.

The exit pupil is the diameter of the light beam which goes out of the binoculars ocular into the human eye pupils. This is calculated by dividing the objective lens diameter to the magnification, as an instance 10×42=42/10=4.2mm.

A human eye pupil is open about 2-3mm during daylight and up to 7mm during the night. The larger is the human eye pupil, more sensible is this to light, therefore, the same rule applies to the exit pupils of the binoculars.

Advantages of 10×42 binoculars over 10×50

It is a good practice to focus on 10×42 binoculars when you are going to use them in general observations, birdwatching, camping & hiking and any other scenarios where the portability and weight matters.

Because of the objective lens diameter is smaller than of the 10×50 version, the binoculars are more lightweight, smaller in size and easier to carry around.

These binoculars I mainly recommend them for birdwatching as you can have a great magnification of 10x and they are very portable. For daylight observations, you don’t need more than a 42mm objective lens diameter. With this diameter, you are still able to do morning/late evening observations, indoors and even night.

TO mention, I have used these binoculars as I own a Nikon Prostaff 7s 10×42 in stargazing, to observe the moon, some constellations and planets, star clusters etc. But in astronomy, you need larger apertures to be able to observe more, and here the 10×50 will come handy.

Enjoying our article 10×42 vs 10×50 binoculars? Give us a share to spread the love!

Advantages of 10×50 binoculars over 10×42

The 10×50 binoculars are good to be used in lower light environments and in special in stargazing/astronomy, where a 50mm objective lens diameter is not that bad in observing some deep-sky objects. This is as well advantaged by the exit pupils of 5mm which can contribute to the low-light observations.

Focusing on the disadvantages of the 10×50 over 10×42 binoculars, these are more heavy and bulky. Not by much, but this can make a difference in special if you decide to use a 10×50 for camping and hiking, where weight and size will matter more than the aperture.

The 10×50 can be also used in the stadium while watching sports but a 10×42 can also handle the job very well as there is more than enough artificial light (if the observations are done during the evening). One another usage of a 10×50 would be during the evening concerts if you are using binoculars, as the 10×42 may not handle very well the low-light situation.

Should I buy both 10×42 and 10×50 binoculars?

I am going, to be honest with you, there is no reason for you to have both 10×42 and 10×50 binoculars, as the difference is small to be noticeable but not big enough for you to take full advantage of both binoculars.

What I would recommend instead an 8×42 and 10×50 which are total two types of binoculars, where the 8×42 have a better field of view, you can use in observing bird flocks and the differences between them are much greater. But in the end, why would you need two pairs of binoculars?

The difference between 10×42 and 25×100 in size.

As an instance, two pair of binoculars may be necessary in the case you want to cover two total areas of observations, as I have 10×42 and 25×100 used in astronomy. (like in the picture above). That would be a strong reason to buy two binoculars.

Instead of having the 10×42 and 10×50, I would recommend investing in a more expensive one which can fit your needs, either the 10×42 vs the 10×50.


Think about your area of observations – are you going to carry more observations during the evening or night? a 10×50 will fit your purposes. But if you are aiming to have a pair of portable binoculars and to wear them all day long for birdwatching and wildlife observations, camping and hiking – the 10×42 would be a much better choice.

No matter which choice you are going to make, ensure that you are going to pick exactly the right binoculars for the main area of observations. You can pick like standard binoculars “good for everything” but ask yourself: what are you going to observe more?

I recommend you to check our complete binoculars buying guide where we covered everything you need to know in over 10 thousand words!.

Related questions

Q1: What binoculars do I need for birdwatching?

A1: When you are going to choose binoculars for birdwatching, you need a magnification of 8x for observing bird flocks or 10x for closer observations. Objective lens diameter of 42mm should be more than enough and for the binoculars to be waterproof, weatherproof and fog proof. More info in our article “How to choose binoculars for birdwatching

Q2: What are the best binoculars for astronomy or stargazing?

A2: For stargazing, you need to focus on magnification if you are observing the moon only and planets, where for deep-sky objects, the aperture or objective lens diameter to be as large as possible. This is required in order to capture more light from the night sky. More info in our other article “How to choose binoculars for stargazing

Q3: How to choose binoculars for hunting?

A3: When you choose binoculars for hunting you have to focus on portability, with a magnification between 8x and 12x if the observations are done during the day. For nighttime hunting, you need night vision binoculars, or if you can afford, thermal imaging binoculars. More information in our other article “How to choose binoculars for hunting“.

Q4: What binoculars should I choose for a safari trip?

A4: In the scenario where you are going on a safari trip, you need a pair of binoculars to balance the power, aperture and portability. A 10x magnification binoculars should be more than enough and with an objective lens diameter of 42mm+ for lower light observations. Quality is going to be our main focus here, and the binoculars with ED elements and multi-coating will contribute. More info in our other article “How to choose binoculars for safari trip

Q5: Are binoculars bad for your eyes?

A5: Binoculars can be bad for your eyes and affect your eyesight in time if you are not going to use them right. There are many minor factors which can affect your eyesight in the long term or contribute to some negative effects of using the binoculars. I recommend you to read our article “Are binoculars bad for your eyes?” for more info.

Thank you for remaining with us until the end of the article, and if you have any questions please do not hesitate to ask us in the comment section below or contact us via our contact page. For now, I will say goodbye and hope to see you around!

Gabriel Mihalcea

Passionate about binoculars, photography and blogging with years experience behind, I love to split my time and observe the beauty of this world with different eyes.

Recent Posts