The primary purpose of binoculars is to magnify the object that you are looking at and they usually consist of two pair of telescopes which are mounted side by side and aligned to focus on one point.
This allows the user to be able to view the object with both eyes, unlike telescope which requires you to use one eye with the other eye closed in viewing.
Now, let’s look at the different types of binoculars.
Binocular Types Explained
Binoculars that have two telescopes pairs are classified into two. The Galilean binoculars and the Prism binoculars.
Galilean Binoculars- Now Opera Glasses
The Galilean binoculars were the first ever binoculars in the binoculars history by Italian astronomer Galileo Galilei in 1609. He used his invention for astronomical observations.
It is believed that he was the first man to see the moon, Jupiter and Saturn planets from earth.
The Galilean binoculars where very basic in design and hence had their shortcomings. These binoculars consist of convex lenses which serve as the objective lenses and concave lenses which are used for the eyepiece.
These Galilean binoculars don’t employ the use of prisms hence they are very lightweight and compact.
However, they have magnification limitations. In present-day binoculars, these Galilean binoculars are now opera glasses with only maximum magnification up to about 4x.
Types of Prism Binoculars
After the invention of the first binoculars, other discoveries followed. The two popular ones we use today are; the roof prism binoculars and the Porro prism binoculars.
Porro Prism Binoculars
In 1854, an Italian Optician Ignazio Porro released a new innovative type of binoculars. This type uses a prism and they were named after him called the Porro prism binoculars.
Then in the 1980s, these Porro prism binoculars were enhanced by a German Manufacturer called Carl Zeiss. These types of binoculars are easily identified by their looks. They have a dogleg shape style.
Porro prism binoculars have their advantages and disadvantages.
- Porro prisms have objective lenses spaced wider than roof prisms, and so can produce a slightly better stereoscopic image than the roof prism design.
- Cheaper to manufacture quality Porro prisms which have the same optical performance as roof prisms so they tend to be cheaper to buy.
- Less compact design than roof prism binoculars
- More moving parts, more to go wrong and harder to make them fully water and dust proof.
Porro prism binoculars can be used for a lot of activities such as marine, birding, wildlife viewing, concerts, and sporting events.
Roof Prism Binoculars
Binoculars using roof prisms may have appeared as early as the 1870s in a design by Achille Victor Emile Daubresse.In 1897 Moritz Hensoldt began marketing roof prism binoculars. Most roof prism binoculars use either the Abbe-Koenig prism or the Schmidt-Pechan prism.
The roof prism system is used to rectify the image for this type of binoculars. The optical path at the objective side and eyepiece side is virtually straight, making it possible for the binoculars to be compact and lightweight. However, High technology is required to manufacture these types of binos. Some customers prefer this type because of its slim and stylish design.
- Compact and slim design
- Less internal parts than Porro prism design, easier to make dust and waterproof.
- Easier to hold for a longer time
- Slightly more expensive than Porro prism because of the precision required to make quality roof prism binoculars.
Ideal general use binoculars that can also be used for bird watching, wildlife viewing, travel, nature viewing, hiking, beach viewing, and sporting events.
Prisms direct light path inside the binoculars. There are two types of prisms commonly use for binoculars.
- BaK-4 -- Created from Barium Crown Glass. Considered as the superior prism because it has a better light transmission.
- BK-7 -- Created from Borosilicate Glass. Good light transmission and more affordable.
Josephine is Content Manager @ Binocularsinght.com, an Electrical Engineering Grad who loves optics. She is an Outdoor Enthusiast and a Writer who likes escaping into the mountains for hiking adventures and enjoys other outdoor activities as well.