Bushnell Spacemaster 15-45x60 Spotting Scopes 782318 belong to well known Bushnell Spacemaster Spotting Scopes Series. Tough, clear, bright and made for any weather, this versatile spotting scope will do it all for a great price.
Exit Pupil of the Bushnell Spacemaster 15-45 x 60
The exit pupil on this bushnell Spacemaster 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. Thus, a 15x45 model has an exit pupil, or useable light, of 3mm (45/15 = 3mm).
Eye Relief : The distance the bushnell 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 of the Spotting Scope 15 45 x 60.
Folded Light Path: A combination optical configuration using lenses and mirrors to create a total bushnell scope length much shorter than the total focal length of the system. This provides a compact design yielding long focal length performance.
Magnification (Power) of the top of the line Spacemaster 15 45X60: Spotting scopes are often referred to by 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. Multi Position Eyepiece Bushnell 's exclusive multi position eyepiece is available on other Bushnell Spacemaster models. This revolutionary eyepiece features an infinite number of viewing positions between straight-thru and 90 degrees - providing flexibility for viewing comfortably in any situation.
Objective Lens Size : The number after the "x" in the formula: (Bushnell 15-45x60) is the diameter of the objective or front lens. The larger the objective lens, the more light that enters the bushnell 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 the higher quality glass yielding brighter images and high edge-to-edge sharpness in the bushnell space master.
Prism Systems: The prism system turns what would otherwise be an upside-down image right-side-up in the Bushnell Spotting Scope.
Roof Prism System: The prisms overlap closely, allowing the objective lenses to line up directly with the eyepiece in the bushnell scope. 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.