Silver halides
Techniques Glossary Silver halides
The light sensitive ingredient in photographic film and papers that is a combination of silver with bromine, fluorine, chlorine or iodine.
Silver halides. Light-sensitive compounds of silver with the halogens (iodine, bromide, etc.). Normally white or creamy yellow in color. Used as the main sensitive constituent of photographic emulsions.
Silver halides are used in photographic film and photographic paper, as well as radiographic film and paper, where silver halide crystals in gelatin are coated on to a film base, glass or paper substrate.
Silver halides - light sensitive crystals used in photographic emulsions, i.e. silver bromide, silver chloride and silver iodide. The change from white to black metallic silver when exposed to light.
The greater amount of reflected light from the brighter object affects more silver halides in the emulsion. The portions of the negative where the most silver halides have been affected are referred to as HIGHLIGHTS.
The fixer stabilizes the emulsion by converting the undeveloped silver halides into water-soluble compounds, which can then be dissolved away. Also called hypo.
In a simple example of this process, a print is first developed in a normal developer and is then transferred to a second developer containing a silver complexing agent capable of dissolving silver halides.
After development the emulsion still contains unexposed and undeveloped silver halides. The film will look cloudy or milky and given exposure to light the remaining silver halides will be reduced to silver.
Natural protein, derived from animals, that's used to suspend silver halides evenly in an emulsion form on the paper and film's surface.
Exposed and processed silver halides on the film emulsion that turn black and form miniature "grain" that make up the image on a piece of film. The equivalent efect at high ISO in digital photography -which is grainless- is "noise".
Fixer (Hypo)-A chemical, sodium thiosulfate, used to remove residual silver halides (grain) from films and prints when processing them. Fixer "fixes" the remaining silver halides in place on either film or prints. Fixer is also called hypo.
Process of converting exposed silver halides (negative or positive film) into visible images
Dew Point:
The temperature to which the air must be cooled for water vapor to condense and form fog or clouds.
-Developer - chemical bath containing reducing agents, which converts exposed silver halides to black metallic silver, making the latent image visible.
-Development - process of converting exposed silver halides to a visible image.
Fixing: Chemical action following development to remove unexposed silver halides, to make the image stable and insensitive to further exposure.
GRAIN - Minute crystals of silver halides in the light-sensitive emulsion of film that react when exposed to light, turning black, are called "grains." (See Graininess of film.) ...
Dev. (Developer)
A Chemical bath which converts exposed silver halides to black metallic silver, so making the latent image on exposed films or photographic papers visible.
(see Latent image) ...
Capture subjects that are photographically worthy. A bad photo is still a bad photo, whether it resides as silver halides or pixels. Digital imaging requires the same creative eye and brutal self-critique as does analog capture.
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Solution, usually based on sodium thiosulphate, in which films or prints are immersed after development to convert the unexposed silver halides in the emulsion to soluble products that can be washed out.
Traditional black and white film was usually silver-based for most of the 20th century. To be more accurate, silver halides were and are used to record and show images. Other metals were used as well, but silver became dominant.
Emulsion: A light sensitive coating on photographic film and paper. An emulsion is made up of silver halides and gelatin.
ammonium fixer
photography, a fixing bath containing NH4+ (univalent ion of ammonia) that is used for removing silver halides from photosensitive emulsions.
amp
abbreviation for ampere.
atmosphere, and drama; to illuminate the story; to separate planes; to suggest depth; to direct attention; to reveal character; to convey time of day; to enrich and, occasionally, bedazzle. Minimum aim: to stimulate microchips and silver halides.
RestrainerA restrainer is added to prevent the developer and the accelerator from working so quickly as to cause chemical fogging, or reduction of un- or underexposed silver halides. Simultaneously the restrainer helps control excessive contrast.
 See also: Silver halide, Silver, Photograph, Image, Photography
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