Ambrotype

The Ambrotype ( Melanotypie, Amphitypie or short Ambro, from the Greek word " ambrotos ", " immortal" ) is a photographic direct positive process, which is produced in the wet collodion process and was used 1852-1890; it was used primarily as a cheap replacement for the daguerreotype.

Method

The visual effect of the Ambrotype is based on a nearly exposed and developed iodine and bromsilberhaltigen collodion on glass. The whitish glass negative is backed with black paper or velvet, giving it its positive image effect (apparent positive); the negative appears due to the dark-field principle against a dark background as a positive. So used is unique.

History and Development

The method continued independently ahead undertaken experiments and discoveries of Sir John Herschel (1839 ), the librarian AA Martin, Frederick Scott Archer ( 1851) and Peter Wickens Fry; a first description comes from the book Plain Directions for Obtaining Photographic Pictures by JH Croucher from the year 1853.

1854 was the American James A. Cutting patented three process improvements and demanded high license fees for use; 1855 M. A. Root coined the term Ambrotype.