What are Silver halide crystals?
A silver halide is a chemical compound that forms between the element silver and one of the halogens. There are three main silver halide compounds widely used in photography: silver iodide, silver chloride, and silver bromate. It is silver chloride and silver bromate that are the most sensitive to light.
When mixed with gelatin, and coated onto film, they are one of the ingredients that sensitizes the surface and allows for photos to be taken.
When the crystals are exposed to light (in a camera or darkroom) they react and turn into a metallic form that creates the latent images. During the process of developing we yield them visible as either a negative or a positive image.
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What is the difference between panchromatic and orthochromatic film?
Orthochromatic film is made with blue-sensitive silver halide crystals, while panchromatic film adds other chemicals to increase the film’s sensitivity into the green and red parts of the spectrum.
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How many layers does a film emulsion have?
There are several layers in a film emulsion and their characteristics vary with each manufacturer.
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How is the emulsion coating applied to the film?
The coating of a film is a layer of emulsion containing microscopic light-sensitive silver halide crystals.
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How does film work?
A photograph is the final result that occurs when a chemical reaction exists between light and sensitive silver grain compounds.
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What is photographic film made from?
Film is composed by two main parts, the base and the emulsion. The film base is usually made of cellulose triacetate, acetate, or polyester. The emulsion is the active ingredient that will capture the final image.