زيادة الكثافة إلى اقصاها بالهيبو والهيدروكينون .. كتاب التحميض والطبع والتكبير

Fifth: Increasing the density to its maximum with hypo and hydroquinone:

comments :

1- This method is considered the most effective means of increasing density.

2- It is always noted that sulfuric acid must be added to the water and not the other way around.

3- It is required in the installation of these solutions that the water be distilled, as it is very likely that the tap water is mixed with chlorine (for sterilization purposes), which is harmful to the process of increasing the density and weakens its effect.

4 - It is certain that the image will be damaged if it is treated in a hypo-solution after increasing its density, or even in water with traces of the fixing solution.

How to mix solutions:

The following order is observed in mixing the solutions:

1- Two parts of solution (B) and one part of solution (A) are added by continuous stirring.

2- Two parts of the solution (C) are added to the above, with continuous stirring.

3- One part of the solution (1) is added to the above, with continuous stirring.

The ability of the solution to survive:

1- The previous solutions have the ability to remain valid for several months, as long as they have not been mixed yet.

2- The mixed solutions (according to the previous arrangement) have no ability to remain except for a period of hours (from 2-3 hours) for the purpose that they were not previously used in any process to increase the density.

3- If the mixed solution is used - even if only once - it must be thrown away immediately after use. In order for it to be reused by mistake, it is possible that it will deposit spots of irregularly shaped silver on the negative.

Pre-intensity negative numbers:

Before starting to fix the image, it should be washed well with water for a period ranging from 5 to 10 minutes, then the gelatin will be hardened with a suitable solution, like the previous explanation of its composition (p.

The time required to treat the negative in the solution:

The image is treated in the previous mixture for about ten minutes at .2°C with continuous stirring, if we want to increase the density to its maximum - only five minutes is enough if we want to increase the density by an average amount. It is best to stick to one negative at a time. This process takes about half a minute.

Sixth: Increasing the density of negative images with positive image dye solutions. Toning Intensifiers:

The defects resulting from the lack of density can be repaired by dyeing the negative by treating it in solutions of coloring the positive images with sulphide sepia toners. And if this method has been called the “intensification” process, in reality it is nothing more than a process of dyeing the negative image in a red or yellow color, so that its transparent areas become more capable of resisting the effect of effective light rays that affect sensitive paper. When printing and enlarging the image. This method is characterized by the fact that it does not have any harmful effect on the ability of the image to remain for a long time without damage. We give an example of one of the solutions that are suitable for performing the previous hypothesis.