Binoculars are one of the most versatile optical tools you can own. Whether you're watching wildlife in the garden, enjoying scenic views on holiday, following the action at a sporting event, spotting aircraft overhead or exploring the night sky, a good pair of binoculars brings the world closer with incredible clarity.

With so many different models available, choosing your first pair can seem confusing. You'll come across specifications like 8x42, hear terms such as exit pupil, eye relief and lens coatings, and wonder whether spending more money really makes a difference.

The good news is that understanding binoculars is much simpler than it first appears. Once you know what the key specifications mean, it becomes much easier to choose a pair that's comfortable to use and perfectly suited to your interests.

In this guide, we'll explain everything you need to know in plain English, from magnification and objective lens size to prism types, waterproofing and lens coatings. By the end, you'll have the confidence to choose the right binoculars for years of enjoyable viewing.

Why Choose Binoculars?

Binoculars offer a unique combination of portability, simplicity and versatility. Unlike many optical devices, they're quick to use, require very little setup and can be taken almost anywhere.

They're ideal for:

• 🦅 Birdwatching and wildlife observation

• 🌄 Walking, hiking and travel

• ⚽ Sporting events and horse racing

• ✈️ Aircraft spotting and airshows

• 🚢 Coastal and marine use

• 🌙 Stargazing and astronomy

• 🎭 Concerts, festivals and outdoor events

A quality pair of binoculars can last for many years, making them a worthwhile investment for anyone who enjoys spending time outdoors or simply wants to see more of the world around them.

Understanding Binocular Numbers (8x42 Explained)

One of the first things you'll notice is a pair of numbers such as:

8x42

These tell you two very important specifications.

Magnification (The First Number)

The first number is the magnification.

An 8x binocular makes an object appear eight times closer.

For example:

• 8x = eight times closer

• 10x = ten times closer

• 12x = twelve times closer

While it might seem tempting to buy the highest magnification available, more isn't always better.

Higher magnification also means:

• More visible hand shake

• Smaller field of view

• Harder to locate moving subjects

• Often heavier binoculars

For most people:

8x offers the easiest viewing experience.

10x provides a little more detail while remaining manageable.

Anything above 12x generally benefits from a tripod.

Objective Lens Diameter (The Second Number)

The second number refers to the diameter of the front lenses, measured in millimetres.

For example:

• 8x32

• 8x42

• 10x50

The larger the objective lens:

✅ More light enters the binoculars

Which usually means:

• Brighter images

• Better low-light performance

• Improved astronomy viewing

The trade-off?

Larger lenses increase size and weight.

What is Exit Pupil?

One of the most overlooked specifications is the exit pupil.

This is the diameter of the beam of light leaving the eyepiece and entering your eye.

It is calculated using a simple formula:

Objective Lens Diameter ÷ Magnification

Examples:

Binocular	Exit Pupil
8x32	4 mm
8x42	5.25 mm
10x42	4.2 mm
10x50	5 mm
7x50	7.1 mm

So why does it matter?

A larger exit pupil generally provides:

• Brighter views

• Easier eye positioning

• Better performance at dusk

• More comfortable astronomy viewing

During the day, your eye's pupil is only around 2–3 mm, so very large exit pupils don't provide much additional benefit.

At night, however, your pupils may open to 5–7 mm, allowing larger exit pupils to deliver noticeably brighter images.

Field of View

The Field of View (FOV) tells you how much of the scene you can see.

A wider field of view makes it easier to:

• Follow birds in flight

• Watch sporting events

• Scan the Milky Way

• Locate wildlife

Generally:

• Lower magnification = wider field

• Higher magnification = narrower field

This is why many birdwatchers prefer 8x42 binoculars over 10x42.

Weight Matters More Than You Think

Many first-time buyers focus entirely on optical performance and forget about comfort.

You may be holding your binoculars for several hours.

Approximate weights:

• Compact binoculars: 250–500 g

• Standard binoculars: 600–900 g

• Large astronomy binoculars: over 1 kg

A heavier pair often offers brighter images but can become tiring during long walks.

If you'll mainly use binoculars for travel or hiking, choosing a lighter model can make a significant difference.

What is a Diopter Adjustment?

Everyone's eyes are slightly different.

Many people have one eye that is stronger than the other.

A diopter adjustment allows you to compensate for this difference.

Most binoculars include a small adjustment ring on one eyepiece.

Setting it only takes a minute:

1. Focus one eye using the centre focus wheel.

2. Close that eye.

3. Adjust the diopter until the second eye is equally sharp.

4. You're done.

Once set, you rarely need to adjust it again.

Lens Coatings Explained

Every time light passes through glass, a small amount is reflected away.

Without coatings, binoculars would appear noticeably darker.

Lens coatings reduce these reflections and increase light transmission.

You'll often see descriptions such as:

Coated

A single coated lens surface.

The most basic option.

Fully Coated

All air-to-glass surfaces have at least one coating.

Produces brighter images than simple coated optics.

Multi-Coated

Several layers are applied to selected surfaces.

Improves contrast and reduces glare.

Fully Multi-Coated (FMC)

The gold standard.

Every air-to-glass surface has multiple coatings.

Benefits include:

• Maximum brightness

• Improved colour accuracy

• Better contrast

• Reduced reflections

• Sharper images

For astronomy and wildlife, Fully Multi-Coated optics are highly recommended.

Prism Types

Most modern binoculars use one of two prism designs.

Roof Prism

✔ Compact

✔ Lightweight

✔ Slim design

Ideal for:

• Birdwatching

• Hiking

• Travel

Porro Prism

✔ Excellent depth perception

✔ Often better value

✔ Very bright images

Slightly larger but often preferred by astronomers.

Waterproof and Fogproof

If you'll be using binoculars outdoors, this is an important feature.

Quality binoculars are often:

• Waterproof

• Nitrogen-filled

• Argon-filled

This prevents:

• Internal fogging

• Moisture damage

• Dust entering the optical system

Ideal for British weather!

Eye Relief

If you wear glasses, you'll want binoculars with generous eye relief.

Eye relief is the distance your eye can sit from the eyepiece while still seeing the full image.

Generally:

• Under 13 mm = not ideal with glasses

• 15–20 mm = comfortable for most spectacle wearers

Many binoculars also include adjustable twist-up eyecups.

Choosing the Right Binoculars

For Birdwatching

8x42

Excellent balance of brightness, field of view and portability.

For Wildlife

8x42 or 10x42

Depending on how much extra reach you want.

For Travel

8x32

Compact, lightweight and easy to carry.

For Astronomy

10x50

A superb all-round choice that reveals:

• The Moon's craters

• Jupiter's four brightest moons

• Star clusters

• Bright nebulae

• The Andromeda Galaxy

• Countless stars invisible to the naked eye

Larger astronomy binoculars such as 15x70 provide even more detail but are usually best mounted on a tripod.

Common Beginner Mistakes

Avoid these common pitfalls:

❌ Buying the highest magnification available.

❌ Ignoring the weight.

❌ Overlooking lens coatings.

❌ Choosing the cheapest optics available.

❌ Forgetting to adjust the diopter.

A quality pair of binoculars with good coatings will often outperform a larger, cheaper pair.

Final Thoughts

Choosing your first binoculars doesn't have to be complicated. Once you understand the key specifications—such as magnification, objective lens size, exit pupil, coatings and weight—you'll be much better equipped to find a pair that suits your interests.

For most beginners, an 8x42 binocular offers the ideal balance of brightness, portability and ease of use. If astronomy is your main focus, a 10x50 model is an excellent step up, revealing an incredible amount of detail in the night sky while still remaining easy to use.

Whether you're watching birds in your garden, taking in spectacular landscapes on holiday, following the action at a sporting event or discovering the wonders of the night sky, the right pair of binoculars can make every view more memorable. By understanding the key features—such as magnification, objective lens size, exit pupil and lens coatings—you'll be able to choose binoculars that perfectly suit your needs and enjoy them for many years to come.