Photo Paper Development

The processing of photographic developer is one or more chemicals that convert the latent to a visible image, developing agents achieve the conversion by reducing the silver halides into silver metal. The conversion occurs within gelatin matrix; the special feature is that the developer only acts those particles of silver halides that are exposed to light.

The time over which development takes place and the type of developer affect the relationship between the density of silver in the developed image and the quantity of light.
 Here are some hints of how it is done:

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