 Smile please
We are going to look at the world of photographs. They are memoirs, they are proofs, and they express how we see the world… photographs actually speak.
A photograph (or photo) is an image created by light falling on light-sensitive  surface – photographic film. The film is coated with light-sensitive silver halide crystals, which record the impression of light on them. This photochemical reaction causes the silver atoms grow into clusters that scatter light, and produce an image, as our eyes would see.
There are other types of photographic films as well, such as Polaroid (that use a special self-developing film, and create a photograph in a minute without any additional development processing) and slide films, and other mediums in which photographs are developed, such as films, videos and digital images.
Perfecting picture
Developing the film is a very crucial process, as it creates the image that we see. Chemicals are used to grow the microscopic silver atoms into silver centres that are visible to the unaided eyes. The developing solutions are made of reducing agents (like Hydroquinone), restrainers to control the reaction (like Bromide ions), and preservatives (like Sodium sulphite) to prevent premature oxidation of silver stoms, as they tend to react with oxygen very easily .
SNAP-ING
The image captured on the film is a negative – opposite of how it is seen by the eye. In other words, the areas touched by light are dark and the unexposed areas are light. The unexposed areas of the film are light sensitive. So, the film is handled in special darkrooms, which are illuminated with safe red light that does not affect it.
Development
- The film is submerged in a tank containing developing chemicals that react with the exposed areas, amplifying the light impressions of the latent image.
- A stop bath treatment with dilute acetic acid is done to prevent the film from overdeveloping.
- A fixative is added to lock in the image.
- The finished negative is washed and rinsed, and hung up to dry.
Printing
- This negative image is used to print a final picture.
- A light source, called an enlarger, is used here.
Its lens focus light through the negative and project it onto light-sensitive paper, forming a positive image.
- The image on this paper is then developed in the same way as the negatives.
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