The famous photographer Jacques Henri Lartigue said that photography is stealing individual moments from time. The term 'moment' used in the first half of the 20th century, when Lartigue worked, was quite natural. But would it have been equally appropriate in the 19th century? Doubtful. It took eight hours to expose first photograph taken by Joseph Nicéphore Niépce at the start of the 19th century. Depending on lighting conditions, it took several minutes to several dozen minutes to expose  the first daguerreotypes. When the new photosensitive substances bromine and chlorine were introduced, the exposure time for daguerreotypes was reduced to 10 seconds.. The exposure time of the emulsion used in daguerreotype photography depended on the composition of the electromagnetic radiation  in the sunlight, and varied from one to several dozen seconds. The time could be shortened depending on the amount of ultraviolet, violet, and blue radiation in the solar spectrum on any given day. With the introduction of bromine silver gelatine techniques at the turn of the 19th and 20th centuries, the exposure time needed to take a photograph was reduced to fractions of a second.