زيادة الكثافة بالزئبق .. كتاب التحميض والطبع والتكبير

Second - Mercury Intensifier:

This process, in turn, takes place in two stages, the first of which is «bleaching» and the second «re-showing to increase the density». This method is suitable when the decrease in the density of the negative image is accompanied by a severe decrease in contrast, as a result of one of the two errors:
(1) Underexposure during photography
(2) Shortening the exposure time in a film that received more than the necessary exposure.

Other solutions to increase the density of mercury:

This process takes place in two stages, the first is to whiten the film, and the second is to re-show.

Action Steps :

(A) The negative image is treated in the previous solution until its black color disappears.

(b) Wash the image well with water.

(C) Blackening of the image (i.e. increasing the density) begins when the image is treated in one of the following solutions:

Savite sodium solution, 10% concentration.

- High Energy Developer appearance solution such as 163-Kodak D

- An ammonia solution with a concentration of 10% (noting that the images that are treated in this last solution are not able to remain for a long time without deterioration).

- If we wanted to increase the contrast significantly, the image should be treated in the following solution after the bleaching process:

Third - Increasing the density by means of silver: Silver Intensifiers

This method is actually a process of natural showing or re-showing of films that have been identified and are characterized by not increasing the size of the grains,

Fourth: Increasing the density of uranium, Uranium Intensifiers

This method is suitable for increasing the density of low-density light negatives that do not lack contrast, such as negatives that did not get sufficient exposure, but they got a correct display. This process is done according to the work steps shown after the solution is installed.