What is a Monocular Used for?

By bmatheus

Though it sounds awkward, the correct term is monocular without an ‘s.’

What Does Monocular Mean?

Hunter looking through a thermal monocular
Monoculars are lightweight and compact, easy to carry in the field while hiking, camping, hunting and backpacking.

A monocular is a type of telescope—an optical device that magnifies distance objects using curved lenses or mirrors that gathers and focuses light or other forms of infrared radiation (in the case of digital, night vision and thermal devices) and to produce an image. Monoculars only have one eyepiece for viewing with one eye. Monoculars are more compact, lighter weight and more cost-effective than binoculars.

A (Very) Brief History of Telescoping Optics

Old magnified devices were primarily made for military and nautical uses.
Old magnified devices were primarily made for military and nautical uses.

A German-born optician named Hans Lippershey is credited with the invention of the first telescoping device. His first experiment was very simple—two lenses held together to magnify objects further away. He called it a “looker.”

In 1608, he filed a patent for his magnifier with the Dutch government but was rejected because the design of the device was too simple. His patent was published which led to many developments in the world of magnified optics.

The first person credited for inventing a telescope is Hans Lippershey.
The first person credited for inventing a telescope is Hans Lippershey.

In 1609, Galileo Galilei used Lippershey’s patent to create a high magnification telescope to view space. His had a magnification range of 3-10x. Though telescopes are mostly used for astronomy, the earliest magnified optics designed throughout the 1700s were primarily for nautical and military uses.

What Do the Numbers on a Monocular Mean?

The most important numbers in the specifications of a monocular are the magnification range and the objective lens—which are displayed like this: 8x32mm. The magnification can be either single or in a range, displayed as such: 4-16x.

Contrasting heat signatures on a man and recently shot boar seen through a thermal imaging monocular
Hog Hunting with the Pulsar Helion XP50.

The magnification (x) is the measurement of how much larger the object appears than what you see with your naked eye. As in the example above, the object is magnified 8 times. Though larger magnifications allow you to see objects much further away, it will decrease your field of view and requires a bigger optic.

The objective lens is the eyepiece located furthest away from your eye. Its diameter is measured in millimeters. The larger the objective lens, the better it gathers light, providing a brighter image. However, the quality of the lens of the monocular matters more in the clarity of the picture. Also, the larger the objective lens, the bulkier the monocular.

A larger monocular will be harder to hold steady for longer periods and more difficult to keep in focus—essentially defeating the purpose of a monocular.

Uses for Monocular

The Pulsar Quantum thermal monocular detects objects up to 1,000 yards away.
The Pulsar Quantum detects objects up to 1,000 yards away.

One of the greatest benefits of a monocular is the size. Monoculars are compact and lightweight. Some are even the size of a writing pen! Many monoculars will fit in your pocket and though there are compact, pocket-size binoculars, quality is (usually) significantly comprised.

Monoculars are perfect for short term scanning, scouting and viewing while:

  • Hiking
  • Camping
  • Hunting
  • Boating
  • Watching concerts, sporting events, opera, ballet and other performances

Specialized monoculars like night vision, thermal and digital are used in law enforcement and military applications, especially when doing surveillance or searching for suspects in the dark.

There are many benefits to using a monocular vs. binoculars:

Weighting as little as 8.8 oz., the pocket-sized Pulsar Axion monocular provides detection range up to 1800 yards away
Weighing as little as 8.8 oz., the pocket-sized Pulsar Axion monocular provides detection range up to 1,800 yards away
  • Because of their size, hikers, backpackers and campers can easily carry them without compromising weight.
  • Since you view using only one eye, you still have a very wide field of view and can remain situationally aware.
  • Monoculars are very easy to use with simple focus adjustments.
  • You can use most monoculars one-handed.
  • Monoculars are less expensive to make, so you get more value per dollar, especially if you are shopping for high-end and specialty monoculars like Pulsar’s thermal Axion monocular.

There are only a few reasons why you should pick binoculars over a monocular when it comes to your outdoor adventures—hunters and bird or wildlife watchers who must scout for long periods will feel more comfortable using binoculars.

Which do you prefer—binoculars or a monocular? Tell us which one and why in the comment section.