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First: Lack of time required for exposure or exposure to light:

As a result of this error, the degree of contrast in the negative image decreases, and the appearance of the image decreases. Details in the shadows in the reproductive image. In order to avoid this defect, the negative image is treated according to the following steps, and this process is called Intensification, i.e. increasing the density in the negative image, or it is called the strengthening process (Fig. 96).

The first way

Action Steps :

(1) The sensitive film or plate is dipped in water.

(2) The following solution is prepared and mixed in the proportions and order shown below.

(3) The film is dipped in the aforementioned solution until the black color disappears from the negative and the color tends to yellow...

(4) Wash the negative with water until the yellow color is completely removed

(e) The film is re-exposed in a strong developer solution, and it is better that it be of the type in which methol and hydroquinone are included as display agents, so the negative image begins to appear, and it is left in the display solution until it reaches the required density.

(6) The film is washed with running water for half an hour.

(7) The film is dried in the usual ways

Notes:

1) This whole process takes place in the normal light of the imaging laboratory.

2) In the event that it is not possible to reach the required degree of density, the process can be repeated according to the previous steps.

Another way to increase density

- Increasing the density with mercury salt:

And it is valid in cases where the lack of density of the negative image is due to.

(A) Under Exposure

(b) Underdevelopment-of-over exposed negative:

That is, this method is suitable for films of low density and low contrast. To remedy this defect, the following solution is prepared:

NB :

It is easy to dissolve mercury chloride salt in warm water, then leave the solution for its temperature to decrease to the required level, and the mercury chloride solution can be kept without damage in a brown bottle.

Action Steps :

1) After preparing the solution that will be used, the negative image and the sensitive surface are placed in it and the basin is moved until the image becomes white.

2) The film that was treated in the previous way should be washed in running water for ten minutes. If any impurities or traces of salts are found on its surface, it can be wiped off with a piece of woolen cotton. Cotton-Wool Pad

3) The negative image begins to appear again in the desired form when it is treated in the next solution, and it is removed when the image reaches the required degree of blackness.

4) After the image reaches the required degree of blackness, it is washed with running water for ten minutes.

5) If it is desired to preserve the negative image for a long time, it is recommended to replace the chloride solution prepared to darken the image with a solution of sodium sulfite (SAD). Sulphite, its concentration is 10%, or to show and blacken the image in a normal appearance solution.

Notes:

1) It should be noted that the image should be washed with water well before the strengthening process.

2) In view of the consequences of the temperature difference between the wash water and the solutions used in the possibility of “softening” the sensitive layer or its separation from the support of the film, we recommend using one of the attempts that you see – the hardening of the sensitive layer before treating the film or the negative that will be repaired.

Such damage may also occur in the sensitive layer as a result of the prolonged stay of the film in the first bleaching solution. Or re-show solution for the purpose of obtaining a greater degree of density.

A third way to increase the density of films:

It is called the Uranium Intensifier method, and it is suitable for strengthening light negative images, i.e. low density, clear details, and does not lack a large degree of contrast. To complete it, prepare the following two solutions