René Dagron

René Prudent Patrice Dagron (17 March 1819 – 13 June 1900) was a French photographer and inventor. He was born in Aillières-Beauvoir, Sarthe, France. On 21 June 1859, Dagron was granted the first microfilm patent in history. Dagron is also considered the inventor of the miniature photographic jewels (French: Bijoux photographiques microscopiques) known as Stanhopes because a modified Stanhope lens is used to view the microscopic picture attached to the lens.

He grew up in rural France but he left for Paris at an early age. In Paris he distinguished himself in the study of Physics and Chemistry. As a chemistry student Dagron became interested in Daguerrotypes when the process of producing them was announced on 19 August 1839. After graduation, Dagron established a photographic portrait studio in Paris. While in Paris Dagron became familiar with the collodion wet plate and collodio-albumen dry plate processes which he would later adapt to his microfilm techniques.

In 1857 John Benjamin Dancer's microfilms were exhibited in Paris for the first time and Dagron immediately saw their potential. He used the concept of microphotography to produce simple microfilm viewers which he would later manufacture and incorporate into novelties and souvenir products as well as other applications. Soon after that, Dagron encountered problems with imitators and people infringing on his patents.

On 21 June 1859, Dagron was granted the first microfilm patent in history and in the same year he introduced his photographic miniature Stanhope toys and jewels during the International Exhibition in Paris.

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