محاليل الاظهار التى تؤدي إلى حبيبات دقيقة .. كتاب أسس التصوير الضوئي

Exposure solutions that lead to fine grains: Fine Grain developers:

As a result of the progress in the manufacture of cameras, and the improvements made to them, the emergence of small-sized cameras (such as the type called Miniature) to satisfy the photographer who tends to include his tools as small as possible, especially after the increase in the number of amateurs, and it was found that many prefer to carry cameras It is small in size and has all the advantages of large machines, which are currently used only in photography studios. As a result of reducing the size of the machines, producers were forced to make small films in order to fit these small machines, and it was found that the small film, after enlarging it, leads to the same result as The big film It has been noted that the apparent problem that may hinder access to technically excellent negatives is the problem of the grains in the sensitive layer. Therefore, film factories tended to take care of finding films that had a small size. The particle size also depends on the composition of the stripper. Therefore, it was necessary to search for solutions that lead to this purpose, and these researches have led to amazing results. The need for display solutions that lead to very fine grains has also increased due to the progress in cinematography and the use of films measuring 16 or 8 millimeters, which increases the need for display solutions of this type of granules.

Highlighting solutions that lead to fine grains: They are solutions with a surface effect mostly, affecting the upper surface of the sensitive layer to a greater degree than their effect on the lower layers, as they do not penetrate into those lower layers with the same strength as other solutions, and this results in the reduction of silver halide In the upper layer only, if the time of exposure exceeds the limit set for this solution, this results in the penetration of the agent into the lower layers of the film and the reduction of the silver halide in these lower layers, then the grains of the metallic silver reduced in contact with each other and form a larger grain and so on (as we mentioned in Figure 70). That is, in order to obtain an excellent result and really fine particles, the time of exposure must be appropriate. Excess exposure may be a reason for increasing the grains despite the use of a bleaching solution of this type. For the use of some bleaching solutions that lead to fine grains, the exposure of the photosensitive film must be increased in proportion to its speed. For example, if the film has a sensitivity value of 32 shair and the lighting conditions require estimating the diaphragm aperture of 48 with a speed of even a second, then it is required when using some of these display solutions that the exposure to light be increased by twice, for example, as if .. the diaphragm aperture is estimated at 45.6 With a speed of a scale of a second, or it is necessary to increase the exposure by four times, such as 5.6: with a speed of one second. In other words, we find that for the sake of what we gain of accuracy in the grains, we lose, on the other hand, the advantage of benefiting from fast-sensitive films. According to the previous example, we find that the photographer Jane used a exposure solution that leads to a fine grain and requires a longer exposure of four times. He reached the same result, or he used a film that was four times slower.
(26 Shiner) is a normal looking solution, and since the use of a slow-moving 26-shine film is a basket that leads to an accurate campaign even with the use of a brightening solution