| dc.description.abstract | Abstract The ambrotype / wet collodion positive on glass is one of the most complex examples of early photographic processes. Like the daguerreotype the ambrotype is also a direct positive process with similar presentation and preservation housings. Nevertheless, the conservation challenges between these two are somewhat different. While conservators have found different solutions for image preservation and recovery for the daguerreotype, useful solutions for the wet collodion positive have to date been rare, especially when it comes to common problems with unvarnished wet collodion positives on glass. This project addresses this gap in numerous ways, by investigating the photographic technology, the consequences of using and handling these types of objects, and what this means for present and future preservation challenges. A review of earlier and current conservation approaches provides insight to the status of analysis, treatment and preservation of wet collodion positives on glass. The thesis provides practical information concerning the photographic technique itself and the different process steps that can affect its permanence. Characteristic housing types and their purposes are described, along with damages and deterioration issues regarding housings, as well as the major problem of the deteriorating of the wet collodion positive itself. Special focus is set on the original housing, its materials and its influence on the stability of the photographic material. For this work, two surveys were undertaken at the Preus Museum and Bergen City Museum to investigate the condition of wet collodion positives on glass in the largest Norwegian collections holding this technique. The aim was to better understand the preservation steps carried out at the time of making, such as varnishing the image layer, and the protective effect of the housing. Findings from the surveys, as well as from earlier treatments and other relevant sources, led to improvements to the original housing system. In addition, different pertinent and useful treatment procedures are described that demonstrate the complexity of the photographic object type with its complex structure of image material, image carrier and housing elements. The work closes with an outline of future research activities and recommendations for the long-term preservation, exhibition and handling of these precious objects. | eng |