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  2. Photographic emulsion - Wikipedia

    en.wikipedia.org/wiki/Photographic_emulsion

    Photographic emulsion is a light-sensitive colloid used in film-based photography. Most commonly, in silver-gelatin photography , it consists of silver halide crystals dispersed in gelatin . The emulsion is usually coated onto a substrate of glass , films (of cellulose nitrate , cellulose acetate or polyester ), paper, or fabric.

  3. Photosensitizer - Wikipedia

    en.wikipedia.org/wiki/Photosensitizer

    Photosensitizers absorb light (hν) and transfer the energy from the incident light into another nearby molecule either directly or by a chemical reaction. Upon absorbing photons of radiation from incident light, photosensitizers transform into an excited singlet state.

  4. Sensitometry - Wikipedia

    en.wikipedia.org/wiki/Sensitometry

    Apart from the widely employed factors such as log-exposure, density, opacity and transmission, sensitometric control of film for television transmission is also particularly concerned with contrast ratios. The definition of contrast ratio is therefore re-stated as follows : 'The ratio between the opacities of the darkest and lightest points in ...

  5. Reciprocity (photography) - Wikipedia

    en.wikipedia.org/wiki/Reciprocity_(photography)

    Light can be considered to be a stream of discrete photons, and a light-sensitive emulsion is composed of discrete light-sensitive grains, usually silver halide crystals. Each grain must absorb a certain number of photons in order for the light-driven reaction to occur and the latent image to form. In particular, if the surface of the silver ...

  6. Exposure (photography) - Wikipedia

    en.wikipedia.org/wiki/Exposure_(photography)

    Outside of this range, it becomes necessary to increase the exposure from the calculated value to account for this characteristic of the emulsion. This characteristic is known as reciprocity failure. The film manufacturer's data sheets should be consulted to arrive at the correction required, as different emulsions have different characteristics.

  7. Photon upconversion - Wikipedia

    en.wikipedia.org/wiki/Photon_upconversion

    The sensitizer then populates its first triplet excited state (3 Sen*) after intersystem crossing (ISC). The excitation energy on the sensitizer then transfers through a Dexter type triplet energy transfer (TET) to a ground state emitter, generating a triplet excited emitter (3 Em*). Two triplet excited emitters then interact in a second energy ...

  8. Photoresist - Wikipedia

    en.wikipedia.org/wiki/Photoresist

    To explain this in graphical form you may have a graph on Log exposure energy versus fraction of resist thickness remaining. The positive resist will be completely removed at the final exposure energy and the negative resist will be completely hardened and insoluble by the end of exposure energy. The slope of this graph is the contrast ratio.

  9. Photographic hypersensitization - Wikipedia

    en.wikipedia.org/wiki/Photographic_hyper...

    A developable photographic latent image forms when crystals of silver halide in an emulsion layer are exposed to light. The initial nucleation phase is chemically and thermodynamically unstable; it is thus temperature sensitive, and involves the production of one, or very few silver atoms as sub-latent image specks in each silver halide crystal.