Types Of Binoculars
Last Updated on June 2, 2021 by Gabriel Goddy
Do you love adventures? Who doesn’t? and what is an adventure without binoculars? Binoculars are great tools in the hands of those who know how to use them. It is important to note that binoculars have several applications. If you read this guide to the end, you’ll see the different types of binoculars and their uses.
What Is A Binocular?
Binoculars are loved by many people for the obvious reason that they let you see details from a distance. As binoculars become less and less expensive, more people enjoy them and the hobbies they permit people to indulge in. Plenty of different people use them for different things.
Binoculars or field glasses are two refracting telescopes mounted side-by-side and aligned to point in the same direction, allowing the viewer to use both eyes (binocular vision) when viewing distant objects. Most binoculars are sized to be held using both hands, although sizes vary widely from opera glasses to large pedestal-mounted military models.
Unlike a (monocular) telescope, binoculars give users a three-dimensional image: each eyepiece presents a slightly different image to each of the viewer’s eyes and the parallax allows the visual cortex to generate an impression of depth.
How binoculars use lenses
The way light bends when it goes from air to a different material (such as water or glass) is called refraction. (For a full explanation of how it works, please see our detailed article on the light.) Refraction is the key to how lenses work—and lenses are the key to binoculars, telescopes, and glasses. But how do we get from light bending in water to a cool pair of binoculars that let us study the moon?
Water sitting in a glass appears to have a straight upper edge, even though it is very slightly curved (the curved edge has a special name: it’s called a meniscus). If you place a glass on top of a newspaper and look straight down, the newsprint looks just the same as normal. That’s because the top of the water is effectively straight.
But if the water had a curved upper surface, the newsprint would look magnified. You can see this for yourself by trying the simple activity “Make a water lens” in our main article on lenses.
Types of lenses
A lens is a curved piece of glass shaped a bit like a lentil. (If you ever wondered where a lens gets its name from, that’s where: lens comes from the Latin word for lentil.) When light rays hit a glass lens, they slow down and bend. If the lens curves like a lentil (like a dome), so its outside is thinner than its middle, it’s called a convex lens.
As light rays enter a convex lens, they bend in toward the middle—as though the lens is sucking them in. That means a convex lens brings distant light rays into a focus. It’s also called a converging lens because it makes light rays come together (converge). Looking at things through convex lenses makes them appear bigger—so convex lenses are used in things like magnifying glasses.
Another kind of lens curves the opposite way, with the middle thinner than the outside. This is called a concave lens. (You can remember this easily if you think that concave lens caves in the middle.) A concave lens makes light rays spread out like the lines of a firework.
Imagine light rays coming into a concave lens and then shooting out in all directions. That’s why a concave lens is sometimes called a diverging lens. It makes light rays shoot out (diverge). Concave lenses are used in movie projectors to make light from the film spread out and cover a bigger area when it hits the wall.
Different Types of Binoculars
- Roof Prism Binoculars
When breaking down binocular types, there are two main categories for modern styles: Roof prism and Porro prism.
Roof prism binoculars are actually the more modern of the two. They’re streamlined, straight-tubed, more lightweight, and more compact than the older-styled Porro prism binoculars. At first glance, they seem to be a much more simplified version of traditional (Porro) binos.
While on the outside they are simplistic, inside they have a much more complex machination than any other style of binoculars. When the light from your target enters the objective lenses, it gets bounced around a series of convoluted pathways before reaching your eyes at the ocular lenses. Through this sequence, roof prism binos can actually produce a much higher magnification power and brighter end imagery.
However, their complex internals can make these binos a bit more expensive than others. They cost more to make, which the manufacturer then passes to the consumer. What It’s Used For Hunting and birdwatching
Much more expensive
Some models have a narrow field of view
- Porro Prism Binoculars
The next major variation of binoculars is Porro prism binoculars. These are actually the original style of bino sets. First developed in the 19th century by Ignazio Porro, this design produced the first real sets of modern binoculars and is still in use today.
With binoculars with Porro prism, the lens and the eyepiece are not aligned. The images are transported via an N-shaped bend. This makes the housing of this type of binoculars wider. An advantage of the Porro prism is that it provides better depth perception. The disadvantage of the Porro prism is that you often focus by moving the eyepiece. This allows dust and water to come into the binoculars. What It’s Used For General use, sporting events, scouting, hiking, and astronomy
Many affordable options
Good 3D imaging
Wide field of view
Bulky and heavy
- Night Vision Binoculars
A standard set of binoculars are going to be next to useless for you if you’re needing them in nighttime or low-light situations. In these cases, you may want to consider a pair of night vision binos.
Night vision devices (such as binoculars) are electronically assisted optics that take the little available light you have and amplify it through a series of photon-enhancing components. At the end of this process, your eyes are treated with usable imagery to help you navigate the dark.
What It’s Used For All low light situations such as spelunking, nighttime exploration or wildlife observations, surveillance, or hunting
Allows you to see in the dark!
- Marine Binoculars
Marine binoculars are specifically designed to be in and around water. They have a wider ocular and objective lens with low to moderate magnification power. When on the high seas (or just whale watching), you’re going to want something that has a larger field of view with a lower magnification.
Too high of magnification will cause a shaky image with just the slightest hand movement. Imagine how hard it would be to keep stable on a rocking boat! Marine binoculars are also generally fog and waterproof. And depending on the model, they may be just as useful under the waves as they are on the surface.
What It’s Used For Marine operations, whale watching, ship gazing, diving, or snorkeling
Rugged with a rubberized armor coating
More expensive than regular binos
Can get lost easily if not equipped with a flotation strap
- Astronomy Binoculars
If you’re an avid stargazer or amateur astronomer, you’re definitely going to want a pair of binoculars designed specifically to explore the heavens. Sure, a telescope is great, but there are times when one just isn’t on-hand or feasible.
For example, let’s say you’re out camping, trying to catch the latest meteor shower. It’s awfully difficult to trace quick-moving meteors or other heavenly bodies on a telescope. But with a little practice, you’ll be a master at detecting and viewing nighttime objects with a good set of astronomy binoculars.
Now, when it comes to this type, there are wildly different variations. Some easily fit in your pocket for spur-of-the-moment views. And some actually require a tripod similar to a telescope. These larger models are very costly and cumbersome; however, their dual ocular lenses give you a much larger field of view than a standard telescope.
What It’s Used For: Examining the night sky and heavenly bodies
More portable than a telescope
Come in a variety of sizes and magnification strengths
Higher-end models are extremely pricey
It May require a tripod
- Opera Glasses
When you think of binoculars, these are probably the last thing that comes to mind. But they’ve been around almost as long as modern binoculars have! And quite frankly, they’re normally the most stylish seats around.
These are primarily used for watching theater productions or opera and musical performances. It can be difficult to catch all of the nuances that actors and musicians put into their craft. But these specifically designed binoculars will help you catch even the most subtle of movements.
They don’t come in super-high magnification powers with the highest powers often being a 4x magnification. But that’s more than enough for what they’re used for. Plus, the low powers make them super easy on your eyes, so fatigue will be at a minimum even through extended periods of time.
What It’s Used For: Viewing theatrical productions, concerts, sporting events
Low magnification powers for maximum viewing pleasure and minimal eye fatigue
With binoculars, you can observe the environment and you can easily bring subjects at a great distance closer. You must own one, you could use it when you need to zoom into someone or something.