Shown as the first number in formats like 10x42.
10x means the object appears 10 times closer than with the naked eye.
Common magnifications: 7x, 8x, 10x, up to 20x or more.The second number in 10x42 refers to the front lens size — here, 42mm.
Larger lenses (like 50mm) allow more light in — better for low-light viewing.