The "salt" you are referring to is actually called silver-halide and are more commonly known as "silver salts". When silver-halide crystals are exposed to light, they form a compound known as "metallic silver"
When silver-halide crystals are exposed to light, they form a compound known as 'metallic silver'. This offers a rich sheen and depth of color to the photo.
Silver Halide
silver Halide
Silver bromide reacts chemically when exposed to light, which is why they use it to make photographic papers.
Photographic plates still darkened when exposed for making spectrograms in areas beyond violet where no visible light could be seen.
Unfortunately, photographic film is not a very efficient light detector. Only about 2% of the light striking photographic film is able to trigger the chemical reaction needed to produce an image. Thus, roughly 98% of the light falling onto photographic film is wasted.
When Rhodopsin in the retina of the eye is exposed to a bright light, the Rhodopsin breaks down into Retinal and Opsin, allowing us to see in many different ranges of light and darkness.rhodopsin molecules break down into molecules of a colorless protein called opsin and a yellowish organic molecule called retainal synthesized from vitamin A
LSD may chemically break down and become inactive when exposed to light.
silver halide
The "salt" you are referring to is actually called silver-halide and are more commonly known as "silver salts". When silver-halide crystals are exposed to light, they form a compound known as "metallic silver"
X-rays will "Fog" photographic plates. That means the plates act as if 'exposed' to light. If the X-rays are intense enough, the plates will appear to be totally exposed.
The short answer is silver. In black and white film and print technology, the silver halides created by exposing the film to light in the camera or on paper under an enlarger, are reduced to silver by the developer and then the remaining halides are washed from the film during the fixing process. In some color photography, ALL of the silver is washed from the film and replaced by dyes introduced during the processing.
Silver bromide reacts chemically when exposed to light, which is why they use it to make photographic papers.
When undeveloped photographic media is exposed to light or radiation (x-rays included), it can be exposed. It can also be damaged by exposure to water or other liquids. Physical damage can also be done by rough transportation, like rips, tears and folds.
A photogram is a photographic image made without a camera by placing objects directly onto the surface of a light-sensitive material such as photographic paper and then exposing it to light. In a darkroom, or a darkened room, objects are arranged on top a piece of photographic material, usually photographic paper. When the operator is satisfied with the arrangement, the photographic material is exposed with light, usually by switching on an enlarger or other artificial light source. The material is then processed, washed and dried. The usual result is a negative shadow image that shows variations in tone that depends upon the transparency of the objects used. Areas of the paper that have received no light appear white; those exposed through transparent or semi-transparent objects appear grey.
Photographic plates still darkened when exposed for making spectrograms in areas beyond violet where no visible light could be seen.
Basically its the same stuff - but you can wrap it differently because it will never be exposed to visible light (in normal usage).
The timer is used to set the intervals at which the light is exposed to the photographic paper. After the timer is turned on, there is a switch that sets the exposure time. This can be put into milliseconds, seconds, or minutes. Often the photographic paper is exposed for around 15 seconds, though this depends largely on the quality of the negative, style of the photographer, contrast of the print, etc.
Unfortunately, photographic film is not a very efficient light detector. Only about 2% of the light striking photographic film is able to trigger the chemical reaction needed to produce an image. Thus, roughly 98% of the light falling onto photographic film is wasted.
That's because photographic plates are sensitive to light.