What does a lens do? What does a lens look like?

Refracted light, with the function of getting the image enlarged and reduced.

Glasses, magnifying glasses, microscopes, telescopes, these are all lenses.

There are convergence and divergence effects.

Lens (lens).

There are six types of lenses in total.

A lens is an optical element made of a transparent substance such as glass, crystal, etc. A lens is a refractor, and its refractive surface is two spheres, or a transparent body with a spherical surface and a flat surface. It forms both real and imaginary images.

Lenses can generally be divided into two main categories: convex lenses and concave lenses. **The part that is thicker than the edge part is called a convex lens, and there are three types: double convex, plano-convex and concave-convex; **The part that is thinner than the edge part is called a concave lens, and there are three types: double concave, flat concave, and convex and concave.

Convex lenses have the function of converging light, so they are also called "converging lenses" and "positive lenses" (which can be used for myopia and reading glasses). Such lenses can be divided into:

a.Biconvex mirror – a lens that is ground into a convex spherical surface on both sides; b.Plano-convex lens - a lens with one side convex and one side flat; c.Concave-convex lens - a lens with one side convex and one side concave.

Concave lenses have the function of diverging light, so they are also called "divergent lenses" and "negative lenses" (which can be used for myopia glasses). This type of lens can be divided into:

a.Biconcave lens – is a lens on both sides; b.Plano-concave lens - it is a lens with one side concave and one side flat; c.Convex and concave lenses - lenses with one convex side and one concave side.

3.Thin lens - a lens with a large thickness of the first part and the radius of curvature of both sides. In the early days, cameras were equipped with only one convex lens, so they were called "single lenses".

With the development of science and technology, modern lenses have several convex and concave lenses of different forms and functions to form a converging lens, called "double lens". The concave lens in the double lens plays the role of correcting various aberrations.

Optical glass has high transparency, purity, colorlessness, uniform texture, and good refractive ability, so it is the main raw material for lens production. Due to the different chemical composition and refractive index, optical glasses have:

1.Flint glass – lead oxide is added to the glass composition to increase the refractive index (; 2.Crown glass - made by adding sodium oxide and calcium oxide to the glass composition to reduce its refractive index (the refractive index of barium crown glass; 3.

Lanthanum corona glass - a variety discovered in recent years, it has the excellent characteristics of high refractive index and low dispersion rate, which provides conditions for the creation of high-grade lenses with large apertures.

A glass or plastic component used in luminaires to change the direction of light or to control the distribution of light distribution.

Lenses are the most basic optical elements that make up the optical system of a microscope, and components such as objective lenses, eyepieces, and condensers are composed of single and multiple lenses. According to its different shapes, it can be divided into two categories: convex lenses (positive lenses) and concave lenses (negative lenses).

When a beam of light parallel to the optical axis intersects at a point after passing through a convex lens, this point is called the "focal point", and the plane that passes through the focal point and is perpendicular to the optical axis is called the "focal plane". There are two focal points, the focal point in the object space is called the "object focus", and the focal plane at the place is called the "object focal plane"; Conversely, the focal point in the image space is called the "image focal point", and the focal plane at the place is called the "image focal plane".

After the light passes through the concave lens, it becomes an upright virtual image, while the convex lens becomes an upright solid image. The real image can be displayed on the screen, while the virtual image cannot.

Here's what the lens looks like:

1. In fact, it is a way to focus the headlights. The traditional headlights are a bulb with a shiny lampshade, this lampshade is called a spotlight shell, and there is also such a cover on the flashlight, and the principle is the same.

2. This lampshade will form a fan-shaped light from the light of the bulb, thereby illuminating the road ahead. The lens headlight uses a smaller and more compact small condenser to concentrate the light into a beam of parallel light, and then diverges into a fan-shaped light through the convex lens.

3. The main components of lens headlights are bulb mounting frame, condenser, convex lens, high and low beam electromagnetic coil and baffle, etc.

The lens construction is as follows:

1P, 2P, 1G1P, 1G2P, 2G2P, 4G, etc., the more lenses, the higher the cost. Therefore, a good quality camera should use a glass lens, which has a better imaging effect than a plastic lens, and plays an important role in astronomy, military, transportation, medicine, art and other fields.

The following is the function of the lens: 1. Illuminating the road: Because the lens has a strong ability to gather light, it is not only bright but also clear to use it to illuminate the road; 2. Long and clear range:

Because the light is very dispersed, its light range is farther and clearer than that of ordinary halogen lamps; 3. Strong penetration: Compared with the headlights with traditional lampheads, the headlights with lens headheads have uniform brightness and strong penetration. The following is an extension of the lens:

1. Single light lens: that is, there is only one light - halogen bulb or xenon bulb is generally used for low beam; The monofocal lens is designed with a corresponding low-beam and high-beam lenses, and the difference between the bifocal lens is that it can be transformed similar to the conversion of far and low beams, and it is usually in a low-beam state; 2. Bifocal lens: It is a lens that can switch between far and near light through the light shield inside the lens; When the shading is closed, it is low beam, and when the shading is open, it is high beam.

Lenses and their applications:

1. The lens with a thick edge in the middle is (convex lens), the lens with a thin edge in the middle is (concave lens), the straight line through the spherical center of the two mirrors is called (main optical axis), and the direction of light propagation through a certain point on it remains unchanged, which is called the (optical center) of the lens, the convex lens has a (convergent) effect on the light, and the concave lens has a (divergent) effect on the light, therefore, the convex lens is also called (convergence) lens, and the concave lens is also called (divergent) lens, and the convex lens can make the parallel rays converge to one point, which is called (focus). The distance from it to the center of light is called (focal length), and the smaller the focal length of the convex lens, the stronger the convergence effect on Sun Sunming's rays.

2. The lens of the camera is equivalent to a (convex lens), the object is far away from the lens, the image is closer (near) to the lens, the object is larger (larger), and the image is (smaller), so the camera becomes a (reduced) and (inverted) (real) image.

3. The lens of the projector is equivalent to a (convex lens), the object is closer to the lens, the image is farther away from the lens, the object is smaller (smaller), and the image is larger (larger), so the projector becomes a (magnified) and (inverted) (real) image.

4. The magnifying glass is a (convex lens), which can magnify the object, so the magnifying glass becomes a (magnifying) and (upright) (virtual) image.

5. The image that can indeed be recorded is called (real image), which and the object are located on both sides of the convex lens, and the object and the virtual image are located on the same side of the convex lens when the virtual image is formed.

6. The imaging law of convex lens (one time the focal length is divided into virtual and real, two times the focal length is divided into size, and the object image movement direction is the same).

7. Parallel rays converge at the (focal point) position after passing through the convex lens, divergent rays converge on the (outside) of the focal point after passing through the convex lens, and convergent rays converge on the (inside) of the focal point after passing through the convex lens, that is, the parallel rays converge normally, the divergent rays slow down the convergence, and the convergent rays accelerate convergence.

8. For myopic eyes, the imaging is too (near), and the convergence of the eyeballs is too (strong), (concave) lenses should be added during correction to make the light (divergence) enter the eye, and the resulting image (outward) shifts. Kaymin.

9. Farsightedness, the imaging is too (far), the convergence of the eyeball is too (weak), and the (convex) lens should be added during correction to make the light (convergence) enter the eye, and the image (inward) is shifted.

10. The eyepiece of the microscope is equivalent to one (magnifying glass), the objective lens is equivalent to one (projector), the eyepiece of the telescope is equivalent to one (magnifying glass), and the objective lens is equivalent to one (camera).