The formation of an image on a flat surface by an optical device and a chemical method of sensitizing that surface to a light source so that the image can be captured permanently is photography.

Seeing extraordinary talent in Phalke, Prof. Gujjar puts him in charge of Kala Bhuvan’s photography studio where Phalke makes several experiments in photochemical processes.

He spends days and nights at the Sir Sayaji Rao library, reading 'Photography depends upon two basic operations - the formation of an image on a flat surface by an optical device, and a chemical method of sensitizing that surface to light so that the image can be captured permanently.

‘The first requirement was met by camera obscura, known since the 16th century and used by artists as an aid to sketching.

‘Wedgwood was the first one to make a light-sensitive material when, in about 1800, he treated white leather and paper with silver salt. He used this technique to make prints of leaves and transparent paintings.

‘The first permanent image produced directly by light was made by Nicephore Niepce in 1823 on a bitumen-coated pewter plate exposed for eight hours. ‘In 1839, Daguerre demonstrated the Daguerrotype in which silver surface on a copper plate was sensitized with iodine vapor.

‘Now Daguerre, when he took over Niepce’s invention, was running the Panorama Theatre animated by light shows and movements in the Place du ----- ‘In 1839, Daguerre demonstrated the Daguerrotype in which silver surface on a copper plate was sensitized with iodine vapor.

‘Now Daguerre, when he took over Niepce’s invention, was running the Panorama Theatre animated by light shows and movements in the Place du -----

‘The camera obscura had generated at one and the same time painting, photography and the diorama.

The wet plates require speed, the luck of an alchemist, and the dexterity of an acrobat. Having shot the picture, you return to the dark room, prepare the dark plate, clean it with cotton and brushes, coat it with viscous collodion, immerse it in silver nitrate solution, recover the exposed plate from the camera, and immerse the plate in developer