وظيفة الخطوات الرئيسة في إظهار الأفلام السالبة الملونة .. كتاب التصوير الملون

The function of the main steps in showing color negative films

1- Color development process:

At this stage, the silver salts (deposited in the three layers of the film) are reduced, and a silver image is formed in each sensitive layer of the three layers, then the reduction process products interact with color problems (color couplers or Color formers) forming a dye image that differs Its color is in each of the three layers of the film, so that in the upper layer (sensitive to blue rays) a form of yellow dye is formed, in the second middle layer (sensitive to green rays) a form of scarlet dye, and in the bottom third layer (sensitive to red rays) a form of a dye of cyan color is formed. i.e. blue green).
To continue (1) washing with water for a relatively long period of time. However, it is certain that the effect of the developer solution persists to a weak extent during the washing period with water, and this matter may not be disliked but rather deliberate in order to allow the residue of the developer solution (with which the film was saturated in the first stage) to complete its effect on the lower layers of the film.

2- Stop the bleaching process and remove traces of the bleaching solution and by-products: It is usual to perform this purpose by following any of the following methods according to the type of color film:

(b) Using a stop bath would stop the effect of the solution that just appeared, and it also interacts with some of the reduction process products, so it is easy to get rid of them by washing in a short period of time following the stopping process.

(H) A stop-fixing-Hardner solution may be used at this stage together with increasing the hardness of the gelatin, followed by washing the film for about five minutes.

Remove the silver image while keeping the dye image

In the third stage, we work to remove the image of silver (with the disposal of the silver halides that were not reduced in the color rendering stage, if a fixation bath mixed with the stopping bath was not used in the previous stage). It is customary to perform this purpose by following any of the following two methods:

(1) To use a solution of Pot__ Ferricyanide salt to dissolve the silver (i.e. it works as a solution for bleaching the image) and then follow it with a fixing solution. (b) To use one solution that performs both the bleaching and fixing processes

1 It is known as the Bleach-Fixing Bath, and in this case, try to replace the potassium ferricyanide with a solution of one of the organic iron salts. The latter method has the following advantages:

- . The ability of this type of solutions to stay for a long time without deterioration. Decreased possibility of undesirable staining of images. For the previous advantages, it is preferable to follow the second method shown in item (b) to show

Color sensitive papers, but not recommended when showing color films. This third stage ends with washing the film with palma. Well washed.

Other operations After the third stage, other operations follow that are not considered major operations, but would maintain the color stability of the image. D What is the colored highlighter made of? The main functions of the salts carried by color film and image display solutions do not differ from those performed by the salts included in the composition of black and white image display solutions, for each of them: (1) Developing agents or Reducing agents

Rapid deterioration (b) preservative salts for reducing agents such as sodium sulfite. ( 7 ) Alkalis to activate reductive alkali , such as carbonate accelerators

sodium or potassium.

(D) anti-fogging agents such as potassium bromide alone or in addition to other solutions of organic materials that perform the same function. (e) In addition to the foregoing, sometimes one or more salts may be added to act as an anti-staining agent, such as Hydroxylamine Hydrochloride.

However, only a certain group of reducing agents are used in color rendering solutions, and as a result of their work, by products are created that interact with color problems (Color Couplern or Color formers), so images are formed from dyes of different colors, each in one of the three layers of the colored film). As we have already mentioned on p. 149). Although many photographers who are accustomed to formulating their own solutions for displaying black and white images, it may seem to them that the matter is difficult or complicated when they are shocked by the chemical names of the salts that act as reducing agents in color display solutions, but it must be said in this regard that there is no complication or complication. It is very difficult, especially if we knew that each of these chemical names, which are not familiar to photographers, have other commercial names that are equal in simplicity to the names of the usual salts used in black and white photography.” And we will show below the chemical names of these salts along with their commercial names as well (1). We decided to keep writing it in Latin letters instead of Arabic, to prevent any possibility of error.

(1)

1 Diethyl Phenylene Diamine Sulphate

Hydrochloride

The first salt is commercially known as Activol or Genochrome sometimes, and assuming that either of the second or third salts is used instead of the first, a weight of sodium sulfite approximately half the weight of the reducing agent itself must be added to the presenting solution.

1-Jacobson, Developing, 15th edition. P. 288-289.

Skin Adverse Effect of Reducing Agents in Color Exposure Solution: Reducing agents used in color imaging may cause harmful skin infections in some individuals. The damage may not appear quickly, but its effect may appear after a while. For this reason, a rubber glove must be used during work. And since some may not feel comfortable when wearing a glove for a long time, or the accumulation of sweat - when wearing the glove - may cause infections in the hands of some, so it is recommended in this case to use Forceps for paper or film when showing it, then wash the hands well with water after finishing work, then dip them In a very dilute solution of acetic acid, then wash thoroughly with soap and water.