الجمع بين المرشحات المعدة لتصحيح الألوان أثناء التكبير .. كتاب التصوير الملون

Combining filters prepared for color correction during magnification: Finance We learned that it is usual in color correction operations by the method of deletion to remove the compound smear from sensitive paper that two filters are used together that differ in their color and also differ in their density sometimes. Assuming that we saw the color correction of the image

By combining two filters whose symbols are as follows:

(Any red filter has a density of 30), (Any cyan filter has a density of 50)

It is possible to say that correcting the colors of the image has required a correction of value
And the last crimson has a density of 30, that is, a similar filter with a density of 50, 50, and it is clear that it is in placing the symbols in this format). simplify it. (-

(40-50) It can also be collected in calculating the filters, assuming that the first image that we prepared first required a correction of the amount, then we saw after that that the image suffers from a red tinge,

( 30 20 - (

B = 2040 80 which calls for us to add the following filters: the sum of the filters that guarantee the required correction, but it is wrong to use three filters of complementary colors together at once, because combining three filters of different colors at one time will not lead to color modification. Not only that, but it also leads to a decrease in the intensity of the light (yellow + scarlet + cyan together are colors that together give rise to a neutral color).

Hence we find that we must work to reduce the number of these filters to two only, by subtracting the smaller number from the whole three numbers. According to the previous example above, the group of filters can be reduced.

From 40 80 20 to 20

This is done by subtracting the smaller number, which is 20, from the numbers shown in the upper row. It is clear that each of the two groups (20 - 60) and (40 20 80) will lead to the same degree of color correction, but the latter requires an unnecessary increase in exposure, as a result of increasing the filter factors, and this is what prompted us to Reducing the number of female candidates to only two instead of three.