Modern preparation of a simple, light-sensitive surface involves forming an emulsion of silver halide crystals in a gelatine, which is then coated onto a film or other support.

[8] This paper triggered a large amount of research in fields of solid-state chemistry and physics, as well more specifically in silver halide photosensitivity phenomena.

[2] Further research into this mechanism revealed that the photographic properties of silver halides (in particular AgBr) were a result of deviations from an ideal crystal structure.

Although impurities in the silver bromide lattice are necessary to encourage Frenkel defect formation, studies by Hamilton have shown that above a specific concentration of impurities, the numbers of defects of interstitial silver ions and positive kinks reduce sharply by several orders of magnitude.

[10] Once trapped, the holes attract mobile, negatively charged defects in the lattice: the interstitial silver vacancy Agv−:[10] The formation of the h.Agv lowers its energy sufficiently to stabilize the complex and reduce the probability of ejection of the hole back into the valance band (the equilibrium constant for hole-complex in the interior of the crystal is estimated at 10−4.

To summarize, as a photographic film is subjected to an image, photons incident on the grain produce electrons which interact to yield silver metal.

The film now has a concentration gradient of silver atom specks based upon varying intensity light across its area, producing an invisible "latent image".

[10] During film development the latent image is intensified by addition of a chemical, typically hydroquinone, that selectivity reduces those grains which contain atoms of silver.

The process, which is sensitive to temperature and concentration, will completely reduce grains to silver metal, intensifying the latent image on the order of 1010 to 1011.

The agent used is sodium thiosulfate, and reacts according to the following equation:[2] An indefinite number of positive prints can be generated from the negative by passing light through it and undertaking the same steps outlined above.

[2] As silver bromide is heated within 100 °C of its melting point, an Arrhenius plot of the ionic conductivity shows the value increasing and "upward-turning".

Other physical properties such as elastic moduli, specific heat, and the electronic energy gap also increase, suggesting the crystal is approaching instability.