طبيعة الألوان .. كتاب التصوير الملون ، للكاتب عبد الفتاح رياض

part One

Nature of colors

Photography is a science and art that relies first on "light", and light is the source of our visual sense of color. Hence, we see that the study of color photography must begin with an introductory study on the nature of the colors of light rays, how they are filtered, the bases for measuring their color, and how to describe them. This is what we discuss in the following chapters:

The first chapter: the colors resulting from the analysis of a white light beam. Part two: optical filters. Chapter Three: Description of Colors.
The first Door

Colors resulting from the analysis of a white light beam

If we pass a white beam of light through a glass prism, this beam will decompose into other colored rays representing the seven known colors of the spectrum: red, orange, yellow, green, blue, indigo, and violet (Fig. 1). The colors of these visible rays overlap with each other without a precise identification between them.

Barrier to receive colored bands

Glass prism

light beam

| An opening through which light passes

(Fig. 1) The decomposition of light as it passes through a glass prism:

If a white light ray passes through a glass prism, it will decompose into rays colored in the seven colors of the spectrum. It is noted that the degree of refraction of ultraviolet rays exceeds the degree of denial of red rays
proportions. Although the colors referred to are seven, there are only three primary colors among them (red, green and blue), if mixed in equal proportions, it will be possible to recreate the white rays. The other colors are mixtures of these primary colors. This can be inferred if we conduct a very simple experiment, summed up in preparing three light sources, spot lights, that emit concentrated light, so that the rays emanating from the first source are blue, from the second is green, and from the third is red. And he will watch. When the colors of the three rays are added in equal quantities and they gather on a plate (black for example) - in their combination they evoke a sense of white color (Fig. 2). This indicates that the white rays consist of only three primary colors.

White rays equal amounts of red + green + blue rays).

black plate

white

green

blue

(Fig. 2) Compose the white rays by addition:

If we prepare three sources, each of which emits an equal amount of rays of different colors (red + green + blue), then the colors of the three rays are added to each other in one patch, then their combination guarantees the recombination of the white rays
Ahmed to perpetuate crimson

= blue + green - blue green (otherwise known as cyan) and green + red = yellow

And assuming that we turn off one of the three light sources (red, green, or blue) and leave the other two sources, the mixing of any two of the colors of the primary rays will result in a new color (Fig. 3) as follows:

And red + blue = scarlet (known as Magenta) and the group of these colors is known (yellow, scarlet, Cyan),

In the name of complementary colors.

green

Cyan green blue

red green yellow

Red, Az Rlah

(Fig. 3) We represented the primary and complementary colors

The triangle with solid lines combines the three primary colors that make up the white rays, and the other triangle (with dashed lines) represents the complementary colors (yellow, scarlet, and bluish green).

It is noted that each main color is matched by its complementary color, so green is matched by scarlet, blue is matched by yellow, and the effect is matched by blue-green (cyan).

cyan red (green fizzy white

I warn - Flemish ( red that too

Anas: Asar (red and green) Q4 is harmful. This is because the complementary color to red is cyan, so if they are added to each other they form white rays, as shown in the following:

Cyan red + white because: red + (green + blue) = white, and therefore the cyan color is called (minus red), i.e. white minus red. And vice versa, in the sense that the red color is called Minus Cyan, i.e. white lacking blue-green.

(b) The color complementary to green is scarlet, because: = green + crimson white i.e. green + (red + blue) = white

Therefore, the scarlet color is called minus green, i.e. white lacking green, and the green color is called minus scarlet.

Minus magenta) i.e. white lacking scarlet.

C - The color complementary to blue is yellow, because: blue + yellow is white i.e. blue + (red + green) = white and therefore the yellow color is called minus blue i.e. white minus blue, just as the blue color is called minus Minus Yellow) i.e. white lacking yellow.