Home » Leedy Advice » Everything Optics – Binoculars to Spotting Scopes

Everything Optics – Binoculars to Spotting Scopes

How do binoculars work?

Before you choose a brand of binoculars, it’s good to understand how binoculars work. There are two sets of lenses – the eyepiece lens, which is closest to your eye and the objective lens at the opposite end, closest to whatever you are viewing. The objective lens captures the image, which is then magnified by the eyepiece lens.

There are three main types of binoculars:

  • Galilean – These use the same structure as the famous Italian astronomer did, with no prism between the two lenses. Today, they are less popular, but some users appreciate the high contrast they provide.
  • Porro prism – As the most common type purchased today, these employ two prisms between the lenses in the shape of a Z. They are easy to identify because the objective end of the binoculars is wider than the eyepiece end. They tend to be larger and heavier.
  • Roof prism – The ends of the binoculars are aligned in a straight line, with two prisms in between. They’re lighter, with a more ergonomic design.

The prism in binoculars shortens the optical path, allowing binoculars to be handheld. It also rectifies what would otherwise be an inverted (upside down) image.

What do the specs on binoculars mean?


To get the most out of your binoculars, it’s important to understand what the basic specs mean. These specs will affect how your binoculars function, from bird watching to gazing at the night sky. Yes, you can do that with binoculars!

Most binoculars are sold with two sets of numbers, such as 10 x 50. The first number is the magnification of the model. The larger the number, the bigger the magnification, which makes a high number perfect for things like sporting events. The second number represents the size of the objective lens in millimetres. Bigger objective lenses produce brighter images, great for stargazing.

Other binocular specs include:

  • Interpupillary distance – The distance between your eyes, which must fit comfortably
  • Dioptre adjustment – Allows for subtle differences between your right and left eye
  • Eye relief – The distance between your eye and the lens, usually created with a rubber cup-like piece and is especially important if you wear glasses
  • Field of view – How wide an area you can see through the binoculars
  • Optical quality – Includes factors such as reduced glare, colour correction, image sharpness, etc.

What are the best binoculars / optics?


The best binoculars / optics are not necessarily the most expensive. They’re the ones that fit your requirements and your chosen activity.

This is a good rule of thumb for all optics. A large telescope that’s difficult for you to transport to a remote observing site may wind up gathering dust, whereas a small scope that’s easy to carry with will get a lot more use. 

Some astronomers have two or more telescopes, such as a Dobsonian with a wide diameter lens for backyard use and a narrower, lighter refractor for travel use with a tripod. Think how you intend to use your binoculars or telescope before you start your selection process. The following list may assist you:

  • How important is a crisp, clear image? For bird watching and safaris, Porro prism binoculars in the 8 x 50 to 12 x 50 range are an excellent choice. That’s important if you hope to make a dent in the roughly 880 birds on the Australian list alone!
  • Will you be looking at something relatively close by or far in the distance across a wide field of view? If it’s the latter, wide angle binoculars are worth looking at.
  • Do you intend to travel or camp with your binoculars? If space is at a premium in hand luggage or a backpack, think about foldable binoculars (ideal for concerts and theatre performances) or small roof prism binoculars.
  • Will the whole family be using them or just you? There are sturdy versions made for kids to use, too.
  • Will you be watching fast-moving animals or observing in low light? You want an image-stabilising model or perhaps night vision optics.
  • Do you intend to use the binoculars in inclement weather or near water? If  so, select waterproof binoculars for that whale watching excursion.
  • There are high-powered binoculars with high magnification used for long-distance viewing and even astronomy. Some models are designed for tripod mounting which offers greater stability. Focus-free (AKA auto-focusing or self-focusing) binoculars have a fixed depth of field and can remove some of the fussing that comes with getting a clear image. Zoom binoculars let you view close up and further away, like the zoom function on a camera.

Where can I purchase optics in Perth?

If you’ve been wondering where to buy binoculars or any type of optical lens, it’s best to see a specialist store – not a department or toy store. 

You want a product that’s well made and will last, plus it’s good to talk to expert staff who can help you select the best models for your use.

In Perth, Leederville Cameras is a one-stop shop for all optics, including binoculars, spotting scopes, telescopes, rangefinders, monoculars, microscopes, and cameras. They not only carry a wide array of top name optical products, but also offer all the accessories you’ll need, like carrying cases, tripods, and lens cleaning supplies. 

There are other reasons to see a specialist retailer like Leederville Cameras, including:

  • Rental options (great for travel or to try out a piece of equipment)
  • Buy now, pay later programs
  • Competitive prices 
  • Free delivery
  • 12-month warranty

Should I get binoculars, a spotting scope or other field optics?


The type of optics you select all depends on your individual requirements. For instance, some people like the versatility of a
 spotting scope. Not only can it be used for wildlife watching, but it can also double as a small ultra-portable telescope. 

The biggest difference between a spotting scope and binoculars is that a spotting scope only engages one eye in viewing. However, spotting scopes have a couple of advantages that some people enjoy. First, the more sophisticated models can accommodate different eyepieces, similar to telescopes, so you can change your field of view and magnification for different uses. Some also allow filters like those for telescopes, which make their use for astronomy more precise.

Another feature of many spotting scopes is they come in an angled configuration that some people find more comfortable. Also, you’ll have the ability to perform both terrestrial and astral viewing (many telescopes are only good for looking at the sky).

Spotting scopes are often a nice segue into telescopes and let you learn about the night sky while also appreciating bird watching and similar activities during the day. If you decide to purchase a telescope, you can still use a spotting scope. You can use it to help locate objects in the sky before zooming in even closer with the larger main lens of the telescope. With perhaps as many as 400 billion stars in our Milky Way galaxy alone, being able to find what you’re looking for is essential!

As you become more familiar with field optics, you may want a toolbox of different instruments for different types of viewing. If you ever attend a ‘star party’ where astronomy enthusiasts gather to observe together, you’ll notice many have a collection of binoculars, spotting scopes, and telescopes for different functions and conditions. Pretty soon, you’ll have a kit of your own that you’ll have great fun adding to over time.

To find out more about binoculars and optics available in Perth, contact the team at Leederville Cameras. Their specialists can help you narrow down your choice and find the perfect products for you. 

Shopping Cart