1. The
science which relates to the
action of
easy on
sensitive bodies in the manufacture of pictures, the
fixation of images, and the like.
2. The
art or process of producing pictures by
this action of light.
The well-focused
optical image is thrown on a surface of metal, glass, paper, or another comfortable stuff, coated with
collodion or gelatin, and sensitized with the chlorides, bromides, or
iodides of silver, or another
salts sensitive to easy. The exposed
plate is then treated with
reducing agents, as pyrogallic acid,
ferrous sulphate, etc, to
develop the
latent image. The
image is then
fixed by
washing off the
excess of unchanged
sensitive salt with
sodium hyposulphite (thiosulphate) or another comfortable reagents.
Origin: Photo-: cf. F. Photographie.
Source: Websters Vocabulary