When
a film's emulsion is struck by light, it
is chemically altered in a manner very similar
to being sunburned. The grains comprising
the emulsion are microscopic and burn-in
individually, creating a scale ranging from
gray to black (or rare, medium and well-done).
A properly exposed piece of film can hold
an enormous amount of precisely burned grains
that will form a very complex image when
developed. Exposed film that is undeveloped
contains a "latent" or hidden
(and very unstable) image - it takes processing
in the lab to make the images appear. If
you open a can of exposed film to see what
it looks like before it's processed, it
will become irreversibly and catastrophically
damaged by light. Don't allow any knucklehead
to do this to you by accident. Mark your
exposed film "Open in darkroom only."
You may not think a lab would do otherwise
but it is possible that your film may be
confused with processed film. It's happened
to me before at major labs in New York and
Los Angeles.
