Understanding binoculars – Buyer’s Guide

Binoculars can be a key component of your outdoor gear, whether wildlife watching, checking out the landscape or just wanting to get a closer look at stuff- binoculars offer the perfect way to do that. However, with so many options and a variety of different focal lengths, magnification and glass specifications all ranging in price from less than £100 to over £1000- how do you know what you’re looking for? Well, today’s article hopes to break down some of the key features to give you a better idea of what you should be looking for when bino shopping!

Note: I am no expert on binos BUT I do own a set AND work in a shop were we regularly sell our own range and branded ranges, helping customers try out and test the best ones for them!

The numbers- what do they all mean?

With any binoculars you will notice two numbers printed somewhere on the body that look a bit like this – 8×32 or 10×42 etc. These refer to the magnification and objective lens diameter respectively; there are a range of options for both factors however the most common is:

Magnification either 8 or 10   

Objective lens diameter either 32 or 42

On other binocular models you can also get smaller or larger options as well but the most common are the ones above. So, what do they actually mean?

Magnification (the first number)

Magnification is the easier of the two numbers to understand. It simply refers to how much something is magnified (how many times bigger it appears). The most common options for magnification are 8 (So the object will be eight times as big) or 10 (so the object is ten times as big) as it would be normally appear. It is really up to personal preference which option you go for, but sometimes the magnification can affect how close to an object you can be (but more on this later!)

Objective lens diameter (the second number)

The objective lens diameter is slightly more complicated, it refers as the name suggests to the diameter (size) of the objective lens in mm. In a normal pair of binos you have two lenses – ocular lens (this is the one closest to your eye) and the objective lens. The size of the objective lens affects how much light gets through to the ocular lens and so it will effect how bright as well as how precise an object appears. For example, an objective lens diameter of 42 is better for low light conditions compared to an objective lens diameter of 32 which is better for general wildlife watching. If you are interested in astronomy, you want a much higher objective lens diameter to deal with the low light- around 60-80mm!

What about field of view?

Field of view (aka, how much can you actually see) is slightly more complicated to work out but essentially, it’s dependant on a combination of factors within the binocular and the magnification. However, for the sake of easy explanation and because unless you are really into specification it won’t matter anyway- the larger the magnification the smaller the field of view.

Other factors:

Although, the magnification and objective lens size are probably the most important factors, there are a few other things you should ask about before buying:

• Weatherproof VS Waterproof– They are NOT the same, weatherproof will protect against light drizzle but for anything else you want waterproof- so unless you plan to use your binoculars a majority of time indoors/through a window, I’d always advise to get waterproof.
• Weight/Size– Always, ALWAYS have a go at holding and carrying the binoculars, I’d even be tempted to try the strap around your neck because what you don’t want is a pair you are going to find too bulky or heavy when out in the field and ending up wishing you just hadn’t bothered.
• Nitrogen filled– Some binos may say nitrogen filled, this means inside the binocular is nitrogen gas- which stops fogging and misting when you go from different temperature areas- eg. getting in or out of your car.
• ED Glass– As you go up prices in binoculars you may see a label that states ED glass/lens which refers to extra low dispersion glass, which helps to prevent fringing and increase clarity on subjects. Its definitely not necessary but up to personal choice.

Overview/Questions to ask when purchasing!

So, I hope this guide has given you a quick overview on all things bino related and you now feel better equipped ready to purchase your own! A few final tips and questions you could ask when purchasing:

• Focus length– I haven’t mentioned this above, as usually binoculars are for long distance- BUT if you want to sit at a window and get a closer look out at your bird feeder just outside, make sure you check the focus length of the binos (how close can an object be and still be in focus!). Usually, its around 2 metres however, some models may be as much as 5 metres- so check before purchasing.
• Case and Strap– Ask about whether the binos you are thinking of purchasing, get a case and strap included, or if you have to buy them separately! Most do have it included but it’s always good to check!
• Warranty– Lots of binoculars are sold with a warranty, check you have this and all the paper work necessary. I sold a guy some binoculars for a whale watch tour- who reappeared 4 weeks later because he’d dropped them off the side of the ship! It was okay, thanks to the warranty but you don’t want to loose your binos to the ocean… It’s also a reminder to wear the strap
• The ones you are actually taking home– Make sure you ALWAYS test the binoculars you plan to take home with you, even if it means taking them out the box and unwrapping etc. etc. It is always best to check you can see through them, and they are the correct specifications before you take them away!