The designation "3-9×40" for a rifle scope provides specific information about its magnification range and objective lens diameter. Let’s break it down:
Magnification (3-9x):
- The first number (3) represents the lowest magnification level. In this case, the scope can magnify an object three times its actual size.
- The second number (9) indicates the highest magnification level, meaning the scope can magnify an object up to nine times its actual size.
- Therefore, a 3-9x scope allows for a variable zoom range between 3x and 9x magnification, enabling the shooter to adjust the magnification based on distance, lighting conditions, and the size of the target.
- Objective Lens Diameter (40):
- The number following the "x" (in this case, 40) indicates the diameter of the objective lens in millimeters.
- A 40mm objective lens allows more light to enter the scope, improving visibility and clarity, especially in low-light conditions. Generally, larger objective lenses can gather more light, resulting in a brighter image. However, they might also make the scope heavier and bulkier.
In summary, a 3-9×40 scope is a variable power scope that offers adjustable magnification from 3x to 9x, with a 40mm diameter objective lens for improved light transmission and image brightness. Such scopes are popular for hunting, target shooting, and general use due to their versatility in various shooting situations.