Why does the camera lens have a film?

The camera is a device that everyone likes. It is a device that uses the principle of optical imaging to form images and uses film to record the images. It is an optical instrument used for photography. In modern social life, there are many devices that can record images, and they all have the characteristics of cameras, such as medical imaging equipment, astronomical observation equipment, etc.

After the light reflected from the scene being photographed is focused through the photographic lens (objective lens) and the shutter that controls the exposure, the scene being photographed forms a latent image on the photosensitive material in the camera obscura, which is processed after processing (i.e. Development, fixation) to form a permanent image. This technology is called photography, which is divided into general photography and professional photography.

So why does the camera lens have a film?

As early as the late 19th century, not long after the invention of the camera, scientist Taylor accidentally discovered a very strange thing. He took photos with a camera and found that the photos taken with a dirty lens were clearer and better. However, he did not conduct in-depth research. Forty years later, this phenomenon attracted the attention of another scientist, Bauer. He did his research and took many photos. As a result, Bauer discovered a secret: adding a layer of film to the lens, although the reflectivity is poor and the lens does not look very bright, actually greatly increases the light transmittance. When a film is coated on the lens, the light of a certain color reflected from the upper and lower surfaces of the film may cancel each other out. In the reflected light, there is no light of this color, so where does the light of this color hide?

It turns out that they all penetrated into the lens through the film, so the light of this color passing through the lens was intensified. From then on, when people manufactured cameras, they often coated the camera lens with a purple film to make the photos taken clearer, more layered, and better. Of course, the technical requirements for processing this film are very high.