 Complete the following phrase:  Prominent London photographer the French-born Antoine Claudet was a user and active promoter of the solar camera, who lectured on the subject to the British Association in Oxford in June 1860, and in 1862 presented On the means of following the small divisions of the scale regulating the distances and enlargement in the solar camera at the British Association for the Advancement of Science in October. Earlier that year he exhibited a number of life-size portrait enlargements from carte de visite negatives at the 