|Commonly Used Phrases and Terms
Magnification is the number of times the object
being viewed is enlarged. Riflescopes are often identified by two
numbers, for example: 6×42. The first number indicates the
magnification or the power of the riflescope, expressed by the
letter “x”, for times. This means that the object being viewed
appears to be 6 times closer than would be seen with the naked
is the ability of the riflescope to change magnification
continuously throughout its design range, providing a low power to
high power range. For example, a 6-24x50mm riflescope has the
ability to magnify the object from 6 to 24 times.
Low Power: Eg. 1.5-6×42,
These riflescopes are ideal at close range and for
shooting moving targets.
Medium Power: Eg. 3-9×50,
These riflescopes are ideal for big-game hunting
at medium range.
High Power: Eg. 6-24×50
riflescopes are best for target shooting, small-game and varmint
The second number in the reference (i.e. 6×42)
indicates the diameter of the objective lens or the front lens. The
larger the objective lens, the better the light transmission, thus
the brighter the image.
coating processes on the lenses and prisms will determine the
brightness and the light gathering of a riflescope thus providing
higher contrast and brighter images. The different types of coatings
Coated = A single layer on at least one lens
Fully Coated = A single layer on all air-to-glass
Multi-Coated = Multiple layers on at least
one lens surface.
Fully Multi-Coated = Multiple layers on
all air-to-glass surfaces.
FIELD OF VIEW (F.O.V):
side-to-side linear measurement of the circular field seen through a
riflescope. It is defined by the width in feet of the area visible
at 100 yards, or in meters at 100m. The higher the magnification,
the narrower the field of view.
of the riflescope’s ability to distinguish fine detail and
This refers to
the size of the small disc of light that exits a riflescope. To
determine the size, divide the objective lens diameter by the power.
For example a 6×42 riflescope will have an exit pupil of 7mm.
This is the
distance a scope can be held away from the human eye and can still
observe the entire field of view. Long Eye Relief (LER) reduces
eyestrain and provides an extra margin of comfort and safety.
to the diameter of the body of a riflescope; that portion between
the belled ends.
be O-ring sealed for complete waterproof protection, and fogproof
which means that they are nitrogen-purged to prevent fogging inside
the optical surfaces. These models are able to keep completely dry
inside after immersion in water, thus suitable for all weather
A condition that
exists when the image being viewed through a riflescope is not
focused precisely on the reticle. Parallax can be detected by an
out-of-focus image or moving image in relation to the reticle as you
move your eye left to right, up and down while looking in the scope.
Scopes with an adjustable objective or turret provides the advantage
of parallax correction.
windage and elevation adjustments affect accuracy and are used to
zero-in on the scope. Windage is the horizontal (left-to-right)
adjustment, usually the side turret of the scope. Elevation is the
vertical (up-and-down) adjustment, usually the top turret of the
scope. Adjustments are usually measured in click value. (1/4 MOA =
1/4” at 100 yards) for finer precision.
A reticle is the
crosshair or pattern placed within the scope, creating a center
point to facilitate aiming at a specific object. Certain reticles
can also be used to measure distance.