A Developed Vision: Pioneering Scottish and French photography from the RSA collections

Dr Thomas Keith, Doorway, Acheson House Edinburgh, salted paper print from negative. Courtesy of The Metropolitan Museum of Art

David Octavius Hill and Robert Adamson, Dennistoun's Monument, Greyfriars Edinburgh, albumen print from paper negative. Courtesy of The Metropolitan Museum of Art

Tree Trunks and Wooden Fence, attributed to John Dudgeon, salted paper print from paper negative. Photo Chris Park

Henri Le Secq, The Foolish Virgins, Facade of Strasbourg Cathedral, 1851, salted paper print waxed paper negaitve