Magnifying glass

Why The Lens of A Magnifying Glass Is A Convex Lens.

First I would introduce the principle of magnifier imaging

The object is placed in the focus, on the other side of the convex lens into an inverted real image, real image has shrunk, such as large, magnified three kinds. The smaller the object distance, the greater the real image. The object is placed in the focal point and the illusion is amplified at the same side of the convex lens. The larger the distance, the larger the illusion. Will not be imaged on the focus. In twice times the focal length will be equal to the big inverted real image.

Many people have the same question that's why the lens of a magnifying glass is a convex lens.

Because the convex lens can enlarge the illusion when the object distance is less than the focal length. The convex lens is the thicker one in the central part. The convex lens is divided into double convex, flat convex and concave (or normal meniscus) forms.

The thin convex lens has the convergent function to also call the concentrating lens, the thicker convex lens has the telescope, the divergence or the convergence function, this with the lens thickness.

The parallel rays (such as sunlight) parallel to the axis (the imagery of the spherical center of the two convex lens) are injected into the convex lens, light on both sides of the lens after two refraction, concentrated on the point of the axis, this is called the focus of the convex lens, the lens on both sides of the lens have a focus, such as a thin lens, The distance between the two focuses to the center of the lens is roughly equal. The focal length of a convex lens is the distance from the focus to the center of the lenses, usually expressed as f. The smaller the spherical radius of the convex lens, the shorter the focal length. The convex lens can be used for magnifying glasses, presbyopia and farsighted people to wear eyeglasses, microscopes, telescope lenses and so on.