What's the difference between a camera and eyes?

When you press the shutter, the light entering the lens group is refracted by the lens group, passes through the aperture shutter, and forms a clear image on the electronic sensor (CCD or CMOS) or film of the camera. The electronic sensor converts the image into an electronic picture and stores it in the storage medium of the camera. In the traditional camera, the image is projected onto the film for exposure, and then the negative is obtained after chemical treatment in the darkroom.

In fact, the core principle of the camera is the convex lens imaging principle, but the lens group with variable focal length is commonly used in the camera, not the convex lens, but the principle is the same. This part is introduced in detail in the physics book of senior two. The landlord girl should be a student, so I might as well borrow it. You can also do an experiment yourself. Light a candle in a dark place and find a convex lens to adjust the distance between the convex lens and the wall back and forth until you see a clear inverted candle.

However, it should be noted that the light can not intersect after passing through the small hole, but is almost direct, so we can only see the very vague virtual image behind the small hole, but can't see the clear image. This experiment is only to illustrate the linear propagation characteristics of light, so it is impossible to apply this principle to the actual camera.

The principle of the camera (the working principle of the camera)

The basic principle of all cameras is the same. No matter what model or size, the camera has a black box with a photosensitive film at one end and a small hole at the other. Its function is to let the light of the image shoot into the black box and reach the film coated with chemical photosensitive materials to make it sensitive. As shown in the figure, a complete camera includes eight main system mechanisms. Of course, these figures simplify the actual situation for the convenience of explanation.

First of all, there must be a framing system, which allows the operator to shoot a suitable field of vision through the framing window and choose the range of scenery he wants. This device is usually a set of lenses or an independent system connected to the lenses.

Followed by photosensitive film, its role is to record the image that reaches the photosensitive film through the lens.

The third is the film winding system. Some cameras use film, others use a single film, but no matter which type, the function of this device is to replace the exposed film with unexposed film.

The fourth is the fuselage, which is a completely closed black box. When taking pictures, only light is allowed to shine through the lens, and most of the camera mechanisms are installed inside.

There are all kinds of things, such as eyes.

Traditional camera imaging process:

1. Focus the scene image on the film through the lens.

2. The photosensitizer on the film changes with the light.

3. The changed photosensitive agent on the film is developed and fixed by the developer.

Form an image that is opposite or complementary to the scene.

Digital camera imaging process:

1. The light passing through the lens is focused on CCD or CMOS.

2.CCD or CMOS converts light into electrical signals.

3. Processed by the processor and recorded in the memory of the camera.

4. The image is formed by computer processing and electro-optical conversion of display, or printed by printer.

Specific process:

A digital camera focuses an image on an imaging element CCD/ CMOS through an optical system, converts the photoelectric signal of each pixel into a digital signal through an A/D converter, and then processes it into a digital image through a DSP and stores it in a storage medium.

The light enters the camera from the lens, and the CCD performs color filtering and light sensing (photoelectric conversion) to "decompose" the photographed object into pixels according to a certain arrangement. These pixels are transmitted to the "analog-to-digital converter" in the form of analog image signals, converted into digital signals, transmitted to the image processor, processed into real images, and then compressed and stored in the storage medium.

One: the reflected light of the scene is converged through the lens to form a latent image on the film, which is the result of the chemical reaction between the light and the emulsion on the film. After development and fixing, an image is formed. The principle of digital camera imaging is different from that of film imaging. It images on a CCD through a lens, and the CCD photoelectrically converts to generate a video signal, and then generates an image through the photoelectric conversion of a display screen.

The main component of a camera is a set of lenses. They are equivalent to a convex lens. When the distance between the object and the convex lens is more than twice the focal length of the convex lens, an inverted and reduced real image can be formed on the negative.

Take a glass and fill it with water. You can see that the glass is thick in the middle and thin at the edge, and it is a convex lens. When you move a glass or an object, sometimes you will see an enlarged upright object, and sometimes you will see an inverted object. In fact, this is an image of an object through the glass.