[Leica] Image preservation - Film doesn't last forever.

[lrzeitlin at aol.com (lrzeitlin at aol.com)]

 Silver images don't last forever. "Daguerreotypes may seem frozen in time, 
but their surfaces are living landscapes. Popular in the middle of the 19th 
century, daguerreotypes were a precursor to photography created by layering 
silver on a copper plate and exposing it to light and various chemicals, 
often including gold. Although daguerreotypes like the one above on the left 
are famous for capturing vivid portraits of their subjects, many have been 
damaged in the 150 years since they were made. The images can become fuzzy 
or faded, or even be wiped away by overzealous cleaners. Hoping to gain some 
insight into how to restore these delicate objects, a team of researchers 
used a scanning electron microscope to zoom in on the surface of 
daguerreotypes?and discovered life. It turns out daguerreotypes have 
parasites. The growths appear to be mostly fungi, though some of the life 
forms remain unidentified. As they eat and digest the metals of a 
daguerreotype, they excrete gold and silver nanoparticles that disfigure the 
image." ?SCIENCE, Feb 14, 2014." - Larry Z