Photographic paper

Photographic paper

The prejudice of many photographers against the color photography occurs from absence of perception of color as forms. You can tell color such that can't be stated black and white. Those who say that the color photography will force out as a result black-and-white, talk nonsense. They don't compete. These are different means to the different purposes.

Edward Weston

Photographic paper — an opaque material on the paper base, intended for obtaining the positive photographic image.

Depending on photographic process photographic paper can be called light-sensitive medium or a special printing paper of photos dyes on the printer.

Photographic paper for use in classical photographic process is covered with the light-sensitive emulsion consisting of a thin gelatinous layer in which, without adjoining with each other, are located crystals of light-sensitive substance — silver halide, less than 0,001 mm in size. As silver halide has yellowish-milk color, the emulsion side of photographic paper has a pale yellow tint. As light-sensitive substance the chloride silver having a maximum of sensitivity in an ultra-violet zone of a range is most often used. Exactly thanks to this substance Ritter found existence of ultraviolet rays (the substance most quicker darkened before a violet section of a range where visually it wasn't found any light).

Photographic paper, as a rule, expose from a negative (a film, a photoplate), using a photographic enlarger, or by means of the contact printing. Under the influence of light in an emulsion there are chemical reactions, the latent image transformed in seen in case of later chemical processing (development, fixation) will be formed.

Effective sensitivity of photographic paper is tens times less than a film and makes usually units and shares of units. Typical exposures when printing — some seconds, while in case of film exposure — the tenth and 100-th fractions of a second.