When the object distance is less than 1 times the focal length, it becomes a vertical magnified virtual image. At this point, the image distance is greater than the object distance, the image is greater than the object, and the object is on the same side. When the object distance is equal to 1 multiple focal length, it will not be imaged, but will be emitted as parallel light. When the object distance is less than 2 times the focal length and greater than 1 times the focal length, the image distance is greater than 2 times the focal length, forming an inverted magnified real image. At this point, the image distance is greater than the object distance, the image is greater than the object, and the object is opposite.

When the object distance is equal to twice the focal length, the image distance is also twice the focal length, forming an inverted real image with equal size. At this time, the object distance is equal to the image distance, and the image is equal to the size of the object, and the object image is different. When the object distance is greater than twice the focal length, the image distance is between 1 and twice the focal length, forming an inverted reduced real image. At this point, the image distance is less than the object distance, the image is less than the object, and the object is opposite.

The law of convex lens imaging is an optical law. In optics, the image that can be presented on the light screen by the convergence of actual light is called the real image; An image that cannot be presented on the screen is called a virtual image.

Lens difference

structure

Convex lens: thin edge and thick middle. At least one surface must be spherical, or both surfaces can be spherical. It can be divided into biconvex, plano-convex and concave-convex lenses.

Concave lens: thick edge and thin middle. At least one surface must be spherical, or both surfaces can be spherical. It can be divided into biconcave lens, plano-concave lens and convex-concave lens.

Act according to light

A convex lens mainly focuses light.

Concave lenses mainly diverge light.

Imaging characteristics

The convex lens is refractive imaging, and the obtained image can be an inverted or reduced real image; Inverted, equal-sized real images; Inverted and enlarged real image; An upright magnified virtual image. Concentrate light.

Concave lens is refractive imaging, which can only form an upright and reduced virtual image. The divergent effect of light.