Field Glasses and Binoculars: Same, Yet Different

Whether you're in the stands at a football game, bird watching, or stargazing, a good pair of binoculars always comes in handy. Binoculars are simply two small telescopes, one for each eye, mounted on a single frame, which magnify a single image in order for better viewing. Unlike a monocular, binoculars allow a user to see with depth and perception by using both eyes simultaneously.

There are two different types of binoculars; field glasses and prismatic binoculars. Although the term field glass is often used interchangeably with binocular, there are differences.

Field glasses are a type of binocular that uses both the objective lens, the large lens through which light first enters, and a second lens inside each tube, which inverts and reverses the image in order for the user to see a right-side-up picture.

Field glasses can magnify an image up to five times. For greater magnification purposes, the simple field glasses would become too long and heavy, and users would instead want to consider the more-popular prismatic binoculars.

Prismatic binoculars use a set of prisms within each tube. When a beam of light passes through the prisms, it reflects and shows greater path length, allowing for higher magnification. This permits the binoculars to be shorter and the separation of the objective lenses to be wider, increasing the stereoscopic effect.

Durability is an advantage of field glasses, making them a popular choice for children. Field glasses have no internal prisms that can be broken or knocked out of alignment due to rough handling. A disadvantage is the magnification strength, which tops out at 5x.

Prismatic binoculars have greater magnification potential (from six to 40 times) in a more compact package; however, the internal prisms can make them more fragile.

No matter what your intended purpose, you can find the perfect pair of binoculars at