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Átirat

how is the negative developed?

how are photographic prints attained?

Black and white negative processing

The film may be soaked in water to swell the gelatin layer.

The developer converts the latent image to metallic silver.[2]

A stop bath,† typically a dilute solution of acetic acid or citric acid, halts the action of the developer. A rinse with clean water may be substituted.

The fixer makes the image permanent and light-resistant by dissolving any remaining silver halide salts. Fixer is sometimes called hypo, a misnomer originating from casually shortened form of the alchemist's name hyposulphite. Neither hyposulphite, hyposulfite, nor hypo is used to mean thiosulfate in modern chemistry.[3]

Washing in clean water removes any remaining fixer. Residual fixer can corrode the silver image, leading to discolouration, staining and fading.[citation needed]

The washing time can be reduced and the fixer more completely removed if a hypo clearing agent is used after the fixer.

Film may be rinsed in a dilute solution of a non-ionic wetting agent to assist uniform drying, which eliminates drying marks caused by hard water. (In very hard water areas, a pre-rinse in distilled water may be required - otherwise the final rinse wetting agent can cause residual ionic calcium on the film to drop out of solution, causing spotting on the negative.)

Film is then dried in a dust-free environment, cut and placed into protective sleeves.

Once the film is processed, it is then referred to as a negative. The negative may now be printed; the negative is placed in an enlarger and projected onto a sheet of photographic paper. There are many different techniques that can be used during the enlargement process. Two examples of enlargement techniques are dodging and burning.

Alternatively (or as well), the negative may be scanned for digital printing or web viewing after adjustment, retouching, and/or manipulation.

† In modern automatic processing machines, the stop bath is replaced by mechanical squeegee or pinching rollers. These treatments remove much of the carried-over alkaline developer, and the acid, when used, neutralizes the alkalinity to reduce the contamination of the fixing bath with the developer.

The latent image goes in a tray of chemicals, called the developer, the image at that point is slowly appearing. The image will then be put in the stop tray which will prevent the chemicals reacting. It is then put into the fix which fixes the chemicals to the paper. lastly, the image is washed in paper to remove the excess chemicals, then hung to dry.

The darkroom process

By Rianna Dulake, Helena Montebello

and

Senay Mustafa

What is the function of the enlarger?

In most darkrooms, an enlarger, an optical apparatus similar to a slide projector, that projects the image of a negative onto a base, finely controls the focus, intensity and duration of light, is used for printmaking. A sheet of photographic paper is exposed to the enlarged image from the negative.

what is the contact print, why and how is it generated?

A contact print is a photographic image produced from film; sometimes from a film negative, and sometimes from a film positive. The defining characteristic of a contact print is that the photographic result is made by exposing through the film negative or positive, onto a light sensitive material that is pressed tightly to the film.

In the dark, or under a safe light, an exposed and developed piece of photographic film is placed emulsion side down, against a piece of photographic paper. Light is briefly shone through the negative. Then, the paper is developed into a contact print. The image in the emulsion has been pressed as close as possible to the photosensitive paper. An exposure box device called a contact printer or a printing frame is sometimes used within a light-controlled space called a darkroom. Enlargers can also be used for this process

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