Whether you’re in the stands at a football game, bird watching, or stargazing, a good pair of binoculars always comes in handy. They 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 (or telescope), binoculars allow a user to see with depth and perception by using both eyes simultaneously.
Field Glasses or Binoculars
There are two different types of binocs; 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.
Aperture – The size of the binoculars’ objective lenses. The second number represented in the numbers describing a set of binoculars, measured in millimeters. Example: In the Steiner 8×22 Predator Binoculars, 22 would represent the aperture.