Before film, glass plates were the standard medium for capturing photographs. There are two types of glass plates: the first, invented by Frederick Scoff Archer was the collodion wet plate, and this was in use in the 1850s. Its replacement came along twenty years later: a silver gelatin dry plate created by Dr. Richard L. Maddox.

Whilst glass plate photography was replaced with film in the consumer market by the early twentieth century, their use continued for many years within the for scientific community, most notably in astronomy. Glass plates were far superior to film for research-quality imaging with their massive resolution. They were extremely stable,  too, and far less likely to bend or distort under environmental conditions which made them ideal for astronomical surveys.

Unfortunately, a great deal of effort is required to conserve such archives. As wihth any physical format, the quality of the content is bound to deteriorate with age. 

But glass slides are also susceptible to relative humidity and temperature, both of which are the most likely cause of deterioration. Other factors that contribute towards a reduction in the longevity of the format include light (too much or constant exposure will cause fading or yellowing), air pollution, as well as factors such as the original quality of the slide’s composite materials.

Of course, glass plates are rather fragile and brittle too, so any physical impact caused by handling or storange errors, could be catastrophic. Caring for and maintanining for such an archive requires time, expertise and cost.  

SDS Scanning has many years’ experience in carefully handling rare and precious glass slide archives. We have the expertise and equipment to convert the content from glass slide and photographic plates to a digital, far-less obsolescent and practical format for study or display.