How do normal cameras work?
To understand instant photography, one
first has the know the basics of conventional photography. Normal
cameras project the image onto the film, which then has to be
developed externally. The film needed for normal pictures consists of
a plastic base which is coated with three layers of light-sensitive
silver compound. Each of the three layers reacts to a different light
spectrum. The top layer is sensitive to blue light, the middle layer
to green light while the bottom layer reacts to red light. When hit
with light, each of the layers react to the light and form metallic
silver in the according layer. This chemical record is then developed
with the help of chemicals called developers.
What is the difference between this and
instant photos?
Instant photographs develop the
photograph inside the camera itself. To facilitate this, special
instant film is required, which is loaded into the camera. Each of
these films results in a print, just like paper that is loaded into a
printer.
How does instant film work?
Instant film consists of the
conventional three light-sensitive layers and special additional
layers for instant photography. Under each of the three color layers,
there lies one developer layer. On top of these layers, lie three
more layers: the image layer, the timing layer and the acid layer.
All these layers together sit on top of a black base layer. There is
one more layer, which sits between the light-sensitive layer and the
image layer. This layer contains the reagent, which together with the
reagent material breaks loose the chain reaction that results in the
developed photograph. At first the reagent material is collected at
the border of the film, but when the picture is snapped, the film is
passed through rollers, which spread the material out into the middle
of the film. As a consequence the reagent reacts and the chain
reaction starts. When the chemicals have taken full effect the
picture will appear on the film.
[332 words]
Keine Kommentare:
Kommentar veröffentlichen