From Lens Coatings to Magnification: Demystifying the Key Features of High-Quality Binoculars

Whether it's birdwatching, hunting, stargazing, or scouting terrain, nothing beats old, good binoculars. Ask anyone who's ever gotten their hands on a pair of Swarovski or Sig sauer binoculars. That's a gold standard for any outdoor experience! 

However, picking the right binoculars is always tricky. That's why we've put together a detailed beginner's binocular shopping guide to make you an informed buyer.

But before you know how to select the best binoculars for various needs, let's go over the basics.

Size of Binoculars

Binoculars come in different sizes and can be broadly categorized as Compact, Mid-size, and Full-size. Technically, each type represents the size of the objective lenses. (It's usually the second number on many models, like a Swarovski binocular 10x42).

It's good to know: There can be significant variations in optics, design and construction, which means same-sized objective lenses can differ in weight and size.

Pro tip: If you like to backpack a binocular, choose a compact model. Want brighter images and a comfortable hold for longer hours? Go for mid-size. Full-size binoculars are on the  heavier side and meant for serious businesses, like hunting, security patrol, or professional needs like ornithology.

Magnification Power

Standard binocular magnifications range between 8 and 10, and each serves a different purpose. Simply put, a magnification of 10 means objects will appear ten times closer than a naked-eye view.

Remember, whether it’s a 8x25, 8x32, or 8x42, they all practically have the same magnification power. If you like to boost things, upgrade to a model like Swarovski Binoculars 10x42. 

Pro tip 1: You may think zoom binoculars are the ultimate pick, but there’s a rub-the not-so-great image quality. So, always give single-magnification models a chance before you settle for a zoomer.

Pro tip 2: A higher magnification sounds like the best binoculars for long distances.

However, that’s not always true. Why? Because a higher magnification means more hand movement. So, anything beyond 10 power is not recommended, especially when you’re in a moving vehicle. Here’s a binocular magnification chart for easy understanding. 

Field of View

One of the most integral specifications of a binocular is the "field of view." Simply put, it's the width of the area that one can view at once when standing at least 1,000 yards away. So, a lower magnification means you have an expanded field of view and vice versa. 

When the field of view is rather narrow, it can be hard to locate small, moving objects, like little birds that often fly away quickly. Also, a smaller field of view means the binocular allows less light to sweep in, leading to darker images.

It's good to know: Binoculars with similar specifications can still have different fields of view by as much as 90 feet wider. So, always check the specifications in detail before purchasing.

Objective Lens Diameter (Aperture)

The amount of light a binocular gets plays a vital role in object imagery. Even though other specs are similar for two binoculars, the one with a larger diameter will get more light and produce brighter images. Take Swarovski Binoculars 10x42 for instance which has high quality optics and produces one of the brightest images. 

The table below helps you understand objective lens diameter choices and magnification power for different uses.  

Exit Pupil

Similar to objective lens diameter, a higher number of exit pupil is responsible for brighter imagery. This is essential in extreme low-light conditions when you are struggling to get a full image of an object from a moving vehicle with shaky hands. 

Exit pupil size= Diameter of the objective lenses / The magnification number

So, for Swarovski Binoculars 10x42, 42 is divided by 10 will give 4.2 mm as the exit pupil diameter. The best binoculars for long distance hunting or birdwatching usually have an exit pupil of 5 mm and above to even out things during low-light conditions.

It's good to know: Exit Pupil size isn’t important during daylight as the best binoculars for long distance have an exit pupil size >2mm. 

Eye Relief

Eye relief is among the must-have features of high quality binoculars for bird watching. Modern binoculars have adjustable eyepieces to draw maximum eye relief value. You need to roll rubber eyecups or twist a collar for eyepiece shortening. 

To measure the eye relief, we calculate the distance between the eye and the eyepiece of a binocular with a visible entire field of view. Eye relief in a binocular is important if one uses prescription glasses. In such cases, you should be looking for an eye relief of >=11mm. 

Lens- Material and Coatings

The glass make-up and the lens coating plays a vital role as they lower the reflection to produce clear and brighter images. So, when buying a pair of binoculars, invest maximum time in test viewing. That way, you will figure out the advancements with the model and pick one for your budget. 

Pro tip: If you use spectacles, choose one with a high view-point. 

Prism Type

Simply put, prisms are optics that channel light from the image right through the binocular and into your eyes. Earlier, “porro prisms” had front wide barrels which weren’t aligned to eyepieces. Today, you have “roof prisms” that offer perfect alignment and don't add to the weight of the binoculars.

Protection 

Protection should be a top priority when buying best binoculars for long distance. Some top models of sig sauer binoculars come with weather resistant features. But don't take things for granted. Manufacturers don't really differentiate between the levels of protection. So, it makes sense to know the basics.

• If you find a pair of Swarovski Binoculars using O-rings, know that they are sealed against moisture. And while it can take on sprinkles and splashdowns, they are vulnerable to extended submersions. 

• Rubber coatings protect against minor drips and crashes.

• Fog-proof binoculars are a good choice in varying weather conditions. They have air purged inside and replaced with nitrogen which means zero chance of condensation.

FAQs: 

What does the different numbers on binoculars mean ?

The numbers on a binocular are the specifications for each model. For example, a Swarovski Binoculars 10x42, it means 10 is the magnification power and 42 is the objective lens diameter in mm. 

What are some extra features of high quality binoculars for bird watching?

Besides high magnification and objective lens diameter, high quality binoculars for birdwatching or hunting come with protection features like rubber coating to save from water splashes. Some models are also fog-proof but they can be a little pricey.