Inventions of Photography – Chapter Five - Collodion Processes: The Collodion Negative, The Ambrotype, The Tintype

A note from the filmmakers:

Not only did the collodion process produce a precise negative, it was also used in two popular direct positive processes, the tintype and the ambrotype. Getting your portrait done, which previously was affordable only for the wealthy, became inexpensive enough for everyone. The processes ushered in a romanticized era of the mobile horse-drawn laboratories that would make tintypes of soldiers during the Civil War.