The principle of the camera obscura is to project the image that is captured by a small hole on the surface. In this way, the size of the image is reduced and can increase its sharpness.
The storage of the obtained image can be done in a sensitive film or in CCD and CMOS sensors or digital memories (in the case of so-called digital photography).
The daguerreotype, invented by Louis Daguerre in 1839, is considered to be the forerunner of modern photography. Daguerre used a layer of silver nitrate on a copper base. The positive was expressed in mercury and the image was fixed when the plate was placed in a solution of sodium chloride or dilute sodium thiosulfate.
George Eastman was a great impeller of photography when, in 1888, he presented the first Kodak camera with a roll of photographic paper. This technique replaced the glass plates. Another important step occurred in 1948, with the launch of the Polaroid technique that allows you to reveal the photos in just one minute.
Currently, photographs are usually retouched with software to eliminate those imperfections that have been recorded and perform all kinds of actions, such as enhancing colors, playing with the focus or superimposing various images on the same, for example.
It is important to bear in mind that, in addition to being used for scientific purposes, photography has managed to become an art. The images taken by the artistic photographers are usually displayed in exhibitions and museums.
The most important parts of a reflex camera are: the objective (formed by the lenses that are responsible for directing the light towards the sensor to achieve the best fidelity to the scene to be captured.) According to the diaphragm, the objective can be more or less luminous), the shutter (consists of a set of blades that allow the passage of light, controlling the amount that must enter, the viewfinder (allows the photographer to see the scene and choose the reason for the image) and the sensor (it is responsible for capturing the information of the scene, it is formed by pixels that are sensitive to light that record the data of the image that will later be processed).