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 .
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 Dagron would later adapt to Dagron 's microfilm techniques .
After graduation , Dagron established a photographic portrait studio in Paris .