Convex lens is a convergent line, so it is also called convergent lens, and concave lens is a divergent light, also known as divergent lens. Borisun Optics sorted out the relevant knowledge points of convex lens and concave lens. Let’s have a look.
1. The phenomenon of convex lens converging sunlight
After the sunlight converges, the brightest and smallest spot will be formed. This small bright spot is formed by the convergence of many actual rays, so the temperature at this bright spot is very high. It can ignite combustibles such as white paper, which is often used to measure the focal length of convex lens. Use a scale to measure the distance between the lens and the small bright spot. It can be regarded as the focal length of this lens.
In reality, using this method to make solar stoves is the first choice for green environmental protection.
2. Reading glasses are convex lenses and concave lenses
Presbyopic glasses are convex lenses. Presbyopic glasses, also known as hundred old mirrors, are a kind of optical products. They are used by people with old eyes. They belong to a kind of convex lens. Presbyopic glasses are mainly to meet the needs of people with presbyopic eyes. Presbyopic glasses are used to supplement the eyesight of the middle-aged and elderly. Like myopia glasses, they have many optical indicators specified in national standards, as well as some special rules of use.
3. Is myopia lens convex lens or concave lens
The lens of myopia glasses is concave lens. The image formed by concave lens is always smaller than the vertical virtual image of the object. Concave lens is mainly used to correct myopia. Myopia is mainly due to the deformation of the lens, resulting in the premature collection of light in front of the retina. The concave lens plays the role of divergent light. The concave lens becomes an upright and reduced virtual image, which lengthens the image distance and falls on the retina.
4. What you see in a convex mirror is reduced
The light emitted by the object is reflected on the convex mirror, and the reflected light diverges, and their extension lines converge into a virtual image behind the mirror. This image is smaller than the real object and looks as if it has been compressed. It can be imagined that when you bend a flat man backward, the image in the mirror is compressed; The more the mirror is bent, the smaller the image is compressed, and the larger the range that can be observed from the convex mirror. So the driver’s rearview mirrors are made of convex mirrors, but the spoon is so curved that what you see in this mirror will not be out of shape.