Today is World Photo Day – celebrating the anniversary of 19th August 1839, when the French government bought the patent to the Daguerreotype photographic process and announced the invention as a gift "Free to the World". Though not the first photographic process invented it was practical for its time and helped to spread the idea of photography around the world.

Caption:circa 1845: Daguerreotype portrait of French painter and photographic pioneer Louis Jacques Mande Daguerre (1789 - 1851). He founded the Diorama in Paris in 1822 and helped to develop the process of imprinting pictures on metal plates using sunlight, leading to the discovery of the daguerrotype process in 1839. (Photo by Jean Baptiste Sabatier-Blot/George Eastman House/Getty Images)

Caption:LONDON, ENGLAND - MAY 13: Daguerreotype images from the 1800s are displayed in the Vintage Room of historic photographs in the Hulton Archive on May 13, 2011 in London, England. The comprehensive archive contains pictures created at the birth of photography in the early 1800s and covers every era and event through to the 21st century. Staff at the Hulton Archive are employed on a wide range of jobs including: conservation, retouching, hand-printing, scanning and archiving. (Photo by Oli Scarff/Getty Images)