Louis-Jacques Daguerre, inventor of the daguerreotype process of photography, put on a free course on his new photographic techniques in Paris, which was attended by the two college student friends Louis Fizeau and Lion Foucault. They watched Daguerre expose a plate in a camera pointing out the window, then after talking about his process for about 30 minutes, he developed the plate using a variety of chemicals to reveal the picture. Although Fizeau and Foucault were impressed they also realised the limitations of the process – it would be wonderful to be able to take portraits, they thought, but the subject could not be expected to remain motionless for 30 minutes. After the course ended they began to experiment to try to speed up the process, and Fizeau had the idea of sensitizing the plate using bromine. Experimentation led to them reducing the exposure time from 30 minutes to 20 seconds. The discovery did not have the impact that it might, however, for other photographic methods were coming into use.

François Arago, a French mathematician, was aware of the great scientific potential of the new methods of photography and, in particular, he was aware of the advances made by Fizeau and Foucault. He approached the two friends in 1845 and suggest that they might attempt to make photographs of an image of the sun produced by a telescope. After multiple attempt, on 2^nd April, 1845, the first surviving daguerrotype photograph of the sun was taken by Fizeau and Foucault. The 5-inch image showed many details including a few sunspots.

Berkowski, a local daguerrotypist whose first name was never published, later made the first solar eclipse photograph on July 28, 1851, also using the daguerrotype process, at the Royal Observatory in Königsberg, Prussia (now Kalinigrad in Russia). A small 6-cm refracting telescope was attached to the 15.8-cm Fraunhofer heliometer and a 84-second exposure was taken shortly after the beginning of totality. By 1858, daily photographic records of the solar surface were taken by Warren de la Rue at the Kew Observatory in England, and by Jules Janssen at the Meudon Observatory near Paris. For the next 14 years, de la Rue record the complete 11 year solar cycle in a series of almost 3000 images that clearly showed sunspots and other features.

 

Reference:

http://www.historyorb.com/day/april/2

http://sunearthday.nasa.gov/2006/locations/firstphoto.php

http://www-history.mcs.st-and.ac.uk/Biographies/Fizeau.html

http://www-history.mcs.st-and.ac.uk/Mathematicians/Arago.html