Spotting Scopes
At Optics Are Us we currently have spotting scopes from Bushnell, Leupold and Nikon. We are in the process of adding spotting scopes from: Alpen, Audubon, Barska, Browning, Brunton, BSA Optics, Burris, Celestron, Eagle Optics, Fujinon, Kowa, Leica, Meade, Pentax, Simmons, Swarovski, Swift Instruments, Tasco, Weaver, Yukon, Zeiss and Zhumell. Below is some terminology for spotting scopes. If you have any more questions or if we don't have what you are looking for listed contact us and we will send you the information and a price.
Spotting Scopes are designed to bring distant objects closer with a higher magnification. They are more stable than binoculars and are excellent for long distance bird watching, observing wildlife, long distance site seeing, astronomy, and surveillance.
Exit Pupil
The exit pupil refers to the size of the column of light that exits a spotting scope. The larger the exit pupil, the brighter the image. To determine the size, divide the objective lens diameter by the power (a 15x45 model has an exit pupil, or useable light, of 3mm).
Eye Relief
The distance a spotting scope can be held away from the eye and still present the full field of view. Extended or long eye relief reduces eyestrain and is ideal for eyeglass wearers.
Field of View (F.O.V.)
Field of view is the side-to-side measurement of the circular viewing field or subject area. It is defined by the width in feet or meters of the area visible at 1000 yards or meters. A wide field of view is better for following fast-moving action or scanning for wildlife. Generally, the higher the magnification, the narrower the field of view.
FOLDED LIGHT PATH
A combination optical configuration using lenses and mirrors to create a total scope length much shorter than the total focal length of the system. This provides a compact design yielding long focal length performance.
Magnification (Power)
Spotting scopes are often referred to by two numbers separated by an "x". For example: 15-45x60. The first number is the power or magnification of the spotting scope. With a 15-45x60 variable power spotting scope, the object being viewed appears to be 15-45 times closer than you would see it with the unaided eye.
Near or Close Focus
The closest you can be to an object and maintain visual clarity.
Objective Lens Size
The second number in the formula: (15-45x60) is the diameter of the objective or front lens. The larger the objective lens, the more light that enters the spotting scope, and the brighter the image.
Prism Glass
Most optical prisms are made from borosilicate (BK-7) glass or barium crown (BAK-4) glass. BAK-4 is higher quality glass yielding brighter images and high edge sharpness.
Prism system turns what would be an upside-down image right-side up.
Roof Prism System - The prisms overlap closely, allowing the objective lenses to line up directly with the eyepiece. The result is a slim, streamlined shape in which the lenses and prisms that magnify and correct the image are in a straight line.
Porro Prism System - The objective or front lens is offset from the eyepiece. Porro prisms provide greater depth perception and generally offer a wider field of view.
