What Is A Monocular?

A monocular is a low powered telescope or spotting scope which is hand held like binoculars but only uses one eye like a telescope. It shares many characteristics with both spotting scopes and binoculars but it is considerably smaller than either. Many monoculars are no larger than your thumb, or as thick as a decent ink pen, and can easily be fitted into your pocket, or purse.

If the occasion is not suited to carry a small pair of binoculars, or a compact spotting scope, there is always the reliable monocular.

Monoculars are really types of telescopes and as such can be described as an optical device that magnifies objects that are some distance away using a series of internal curved lenses and/or mirrors that focuses light (or other infrared radiation) to create an image. Monoculars are smaller in size, lightweight and easy to carry. This makes the monocular much more convenient, less of a struggle to carry, and a very handy piece of kit to own.

Seeing In The Dark (Night Vision)

There are night vision monoculars which allow you to see objects in the dark with a great deal of clarity. This allows you to spot wild predators with no fear of attack. These same monoculars work perfectly well in daylight too. Offering clear vision during the day and at night, and they often have a decent battery life too.

What Do The Numbers Mean On A Monocular?

The numbers imprinted on the body of the monocular refer to the magnification and the objective lens. They are displayed like this: 8×32 or 10×40. The number 8x or 10x refer to the magnification that the lens can supply. For instance 8x means the object is seen 8 times (or 10 times) closer than it actually is. The other number refers to the field of vision which is the area width you are able to see through the monocular. 

The Objective Lens

The higher the magnification on the monocular, the lower the field of view and the lower light input too. Which means the higher the magnification the darker the image will appear. The objective lens size affects the level of light that enters the eyepiece. It’s this lens size that is quoted on the monocular’s body as the second number in this case 32 (or 40). So it’s magnification and then objective lens size. The bigger the objective lens, the more light enters the eyepiece, the brighter the image becomes.

As the objective lens size is increased, the larger the monocular becomes and the heavier it becomes too. This increase in weight will affect the length of time the monocular can be held steady. So a larger monocular will be harder to keep still, harder to focus and too bulky to carry.

What Are Monoculars Used For?

Monoculars come in many sizes, starting from pen size, pocket size, and so on. There are also many binoculars available in small sizes but many lose quality as the size reduces. This is not the case with monoculars.  So what are monoculars used for? Monoculars are perfect for use whilst:

• Camping
• Bird Watching
• Hunting
• Target Spotting
• Hiking
• Boating
• Watching Concerts
• At Sporting Events
• As An Opera Glass
• Watching Ballet
• Theatre Watching
• And Much More

There are monoculars that are fitted with night vision, thermal and digital which are used by the military, and for police work. Most usually when working on surveillance cases or just searching for criminals in the dark.

Why Are Monoculars So Popular With Outdoorsmen?

There are many reasons to pack a monocular when on a trip outdoors, many hunters and bird watchers wouldn’t leave home without their monocular because;

• They are lightweight and easy to carry
• Monoculars are easy to use, most can be used one handed
• They cost less than binoculars or spotting scopes of a compared magnification
• Monoculars are easy to use, with simplistic focus adjustment increments
• As you are only using one eye, you have a wide field of vision, and you can be aware of any situations nearby

How Is The Monocular’s Viewing Mechanism Created?

Most monoculars utilize the system invented by Ignatio Porro in 1854. This system was invented for binoculars and works on the principle of a prism and a curved lens. The lens captures light from long distances and amplifies it, whilst the prism inverts the image. Due to the shape of the lens, the image would be inverted if not for the prism. The lens and the prism are the most expensive parts of the monocular generally, and this explains why monoculars are less expensive than binoculars.

Are There Any Disadvantages To Using A Monocular?

If you were to use a monocular for an extended period of time, you are likely to suffer from eye strain. This is because a monocular puts extra strain on the eye using it. This is less likely to happen using binoculars as both eyes are taking the strain. But this eye strain is no more than would be expected using a telescope or a spotting scope.

How Much Will A Monocular Cost To Buy?

With many monoculars being manufactured in Japan, Russia, Germany and China, with the majority being made in China. As for the price, they vary widely with high spec models costing around the £300.00 mark and the cheapest models costing around £10.00 There is a wide range of products and prices, but many good value models seem to be in the £50.00 to £150.00 range.

What’s The Difference Between A Monocular And A Telescope?

They are both of similar design, but there are 2 main differences, telescopes tend to be larger, heavier models, and telescopes also have a much higher magnification range and also a larger objective lens diameter. Monocular sizes tend to be limited to 12 times magnification and an objective lens size of around 50 mm. Whereas a hand-held  telescope has a maximum magnification size of 16 times and an objective lens diameter of around 52 mm.

What’s Better Binoculars Or Monoculars?

This question comes up often, and it depends on the circumstances they are going to be used in. But in many cases monoculars win hands down. For instance:

• Monoculars weigh less than binoculars (½ as much) this makes them more convenient.
• Binoculars cause less eye fatigue over long periods of use.
• Monoculars are better suited for night vision and thermal vision usage.
• Monoculars are usually priced better than binoculars when compared by quality.
• Monoculars are easier to use than binoculars.
• Monoculars leave one eye free to be aware of the terrain/hostile attack.

Frequently Asked Questions