What is the connection between photography and mollusks?

Answer 1

Bromine compounds were in use long before bromine was identified and isolated. A purple excretion from certain mollusks was long ago used to make purple dye known as "Tyrian purple." It is now known that this excretion is a bromine compound. http://www.mii.org/Minerals/photobromine.html Bromine compounds have a number of applications in Photography. Several compounds are used to make the all-important light-sensitive component of a photographic emulsion - without these bromine compounds your pictures would not capture sufficient light. Other bromine compounds are used as an ingredient in photo development - without which your pictures would not be able to be developed. http://www.azom.com/details.asp?ArticleID=3528 A sepia tone is a reddish brown monochrome tint. When applied to a photo, it gives the picture a warm, antique feeling. Sepia is a Greek word meaning "cuttlefish," a squidlike mollusk which secretes a dark brown ink or pigment. The ink derived from the secretion of the cuttlefish was used as a primitive pigment, although it has been replaced today by modern dyes. In photography, sepia refers to a brown tint which could occur in photos treated with a gold toning bath. Over time, the photo would fade into the reddish-brown tint we associate with sepia now. http://graphicssoft.about.com/od/glossary/g/sepia.htm