Upon exposure to the light forming the image, the sensitive material undergoes changes in its structure, a latent (but reversed) image usually called a negative is formed, and the image becomes visible by development and permanent by fixing with sodium thiosulfate, called “hypo.” With modern materials, the processing may take place immediately or may be delayed for weeks or months.
The essential elements of the image are usually established immediately at the time of exposure.
An effective photograph can disseminate information about humanity and nature, record the visible world, and extend human knowledge and understanding.
For all these reasons, photography has aptly been called the most important invention since the printing press.camera obscura, a dark chamber or room with a hole (later a lens) in one wall, through which images of objects outside the room were projected on the opposite wall.
He demonstrated the fact by using sunlight to record words on the salts, but he made no attempt to preserve the images permanently.
His discovery, in combination with the camera obscura, provided the basic technology necessary for photography.While artists in subsequent centuries commonly used variations on the camera obscura to create images they could trace, the results from these devices depended on the artist’s drawing skills, and so scientists continued to search for a method to reproduce images completely mechanically.Johann Heinrich Schulze proved that the darkening of silver salts, a phenomenon known since the 16th century and possibly earlier, was caused by light and not heat.Our editors will review what you’ve submitted and determine whether to revise the article.Join Britannica's Publishing Partner Program and our community of experts to gain a global audience for your work! In order to understand them, one must first understand the characteristics of the process itself.With the lines between genres becoming unclear, there are still works that cannot be considered part of any category, or are consider part of many.Creativity evolved with the medium, but so did the ways of manifesting it.The photograph possesses, in the popular mind, such apparent accuracy that the adage “the camera does not lie” has become an accepted, if erroneous, cliché.This understanding of photography’s supposed objectivity has dominated evaluations of its role in the arts.He or she chooses the vantage point and the exact moment of exposure.The photographer perceives the essential qualities of the subject and interprets it according to his or her judgment, taste, and involvement.