In the early 19th century, scientists, philosophers and artists needed to have an objective and positive knowledge of the reality. The invention of photography helped them to acquire the needed knowledge. It, also, greatly affected the visual art. Artists were influenced by the invention of the camera, because it provided them a cropped composition. It also showed the tonal effects of light and dark with better detail; so it was easier for artists to capture the tone in their compositions. Photography had an immediate effect not only on portrait painters but also on landscape painters. By the time of the Impressionists, technical advances had led to the development of the snapshot camera. Blurring, unusual juxtapositions and the accidental cropping off of figures in snapshots created the sense of movement and spontaneity that the Impressionist artists wanted to achieve. For example, Edmund Greacen captured the heat of a summer day by blurring his image and enjoying the play of light and color in the reflections in the water.However, for impressionist artists, photography represented how something looked but not how one could see it.