A preliminary understanding of cameras

1826, a French scientist, Joseph Nipps, took the world's first photo in his home, entitled "Scenery outside the window of Legolas".

Open Baidu APP to see more high-definition pictures.

2. The imaging principle of the camera

Blocking a plate with a small hole between the screen and the object will form a reflection of the object on the screen. We call this phenomenon pinhole imaging. Move the midplane back and forth, and the image size will change accordingly. This phenomenon reflects the essence of light propagation along a straight line.

3. Classification of cameras

Cameras are divided into film cameras and digital cameras.

Film camera: film cameras, that is, traditional cameras, are divided into monocular cameras and binocular cameras. Film cameras only use negatives. Therefore, in terms of cost, consumers need to buy negative films, develop them into photos, and also need to develop negative films and photographic paper. Calculate the cost of each roll of negative film is about 60 yuan, and if it is positive film, it is about 40 yuan.

Digital camera:

Digital camera, English full name: Digital Still Camera (DSC), short name: Digital Camera (DC), short name of digital camera, also known as digital camera. Digital camera is a kind of camera that uses electronic sensors to convert optical images into electronic data.

According to the use, it is divided into: SLR camera, micro camera, card camera, telephoto camera and household camera. The principle of digital camera recording images on film through silver bromide's chemical changes is different from that of ordinary cameras. The sensor of digital camera is photosensitive charge coupled device (CCD) or complementary metal oxide semiconductor (CMOS). Before an image is transmitted to a computer, it is usually stored in a digital storage device (usually using flash memory; Floppy disks and rewritable compact discs (CD-RW) are rarely used in digital camera equipment.

4. Camera composition: body+lens

Body: When we pick up the camera, the first thing we see is an opaque black box, which we call the body. The fuselage is the general carrier connecting the optical, mechanical and electronic parts of the camera. Its front end is equipped with a camera lens. Digital camera body is equipped with electronic components such as image sensor, digital image processor and image memory. The camera body of the traditional film camera is filled with film, and various optical, mechanical and electronic components are installed in the middle of the film, so that the camera becomes a whole. In addition, all kinds of photographic accessories and auxiliary equipment should also be connected to the fuselage when used. Therefore, the camera body is generally made of metal or injection molding material with high processing strength.

Lens: The lens is also called photographic objective. The role of the lens is to make the external scene form a clear image on the film plane in the camera black box. Just like our human eyes can clearly reflect what we see on the retina to our eyeballs. Lens is an important part of a camera. Students should love the camera as much as their own eyes.