Aperture - Refers to the diameter of the objective lens in millimeters. Aperture is the second number in the 8x42 formula on binoculars.
Binocular - an optic tool that blends an image seen by both eyes into a single image. Binoculars are available in different powers or magnifications.
Digital Binocular - a binocular and digital camera combined.
Eyepiece - the lens at the viewing end of a telescope. The eyepiece enlarges an image captured by the telescope.
Eye Relief - A function for eyeglass wearers that allows your eyes to be at a greater distance from the eyepiece.
Field of View - The size of the "window" you see through when looking through binoculars.
Giant Binoculars - Binoculars for astronomy, with apertures of 70mm, 80mm, 100mm or greater.
Image Intensification - Night vision technology that collects light energy from its surroundings.
Liquid Crystal Display (LCD) - A display technology common in digital cameras that increases visibility and reduces eyestrain.
Magnification - Increases the apparent size of an object. Magnification is the first number in the 8x42 formula on binoculars.
Monocular - mini scopes such as spyglasses and pen scopes that allow a magnified view of an image seen from one eye.
Night Vision - improves visual capabilities during nighttime, or in low light surroundings. Used commonly by the military, aviators and by law enforcement for surveillance. Night vision is also a useful tool for nocturnal hunters, hikers and birders.
Opera Glasses - pocket-sized, and usually decorative compact binoculars for theater-goers.
Phosphor - A coating that emits light when excited by energy. The screen on night vision equipment is green phosphor.
Rangefinders - an optical measuring instrument that finds the distance of an object. Useful tools for golfers, mariners, hunters and for target practice.
Riflescopes - sights for hunting that mount onto a rifle and make targets appear closer then they actually are.
Spotting Scopes - a telescope that is primarily intended for land viewing, as opposed to astronomical.
Telescope -intensely magnifies distant objects for celestial exploring. Telescopes come in Refractor and Reflector models.
Thermal Imaging - Night vision technology that captures light from heat emissions.
