{"id":2084,"date":"2020-02-10T13:41:15","date_gmt":"2020-02-10T12:41:15","guid":{"rendered":"https:\/\/www.photographe-corporate.net\/study-of-light-in-photography\/"},"modified":"2023-02-01T13:15:24","modified_gmt":"2023-02-01T12:15:24","slug":"study-of-light-in-photography","status":"publish","type":"post","link":"https:\/\/www.photographe-corporate.net\/en\/study-of-light-in-photography\/","title":{"rendered":"Study of light in photography"},"content":{"rendered":"\n

The light<\/h2>\n\n

Photography, a word that has its origin in the ancient Greek<\/p>\n\n

Photo<\/strong> = Photon which means light; Graphie<\/strong> = to write, to draw<\/p>\n\n

Light is a set of electro-magnetic waves to which our human eyes are sensitive. A wave is characterized by its wavelength.<\/p>\n\n

A human eye is sensitive to waves between 400 and 700 nanometers. 1 nanometer (nm) = 10<\/em> -9<\/em><\/sup> m = 0.000000001 meter<\/p>\n\n

In this range of 400 to 700 nm, each wavelength corresponds to a different visual sensation<\/strong>, so 1 color.<\/p>\n\n

In this visible spectrum, there are 3 main colored areas:<\/p>\n\n

\"Illustration
Illustration of the visible light spectrum – @copyright<\/figcaption><\/figure>\n

These 3 colors BLUE \/ GREEN \/ RED are the fundamental primary colors<\/p>\n\n

They are the basis of human vision and photo systems.<\/p>\n\n

Indeed, on the human retina, there are cones sensitive to colors.<\/p>\n\n

1\/3 of these cones are sensitive to BLUE<\/p>\n\n

1\/3 of these cones are sensitive to GREEN<\/p>\n\n

1\/3 of these cones are sensitive to RED<\/p>\n\n

In a color silver film, which has 3 layers, there is a layer sensitive to BLUE, a layer sensitive to GREEN and a layer sensitive to RED.<\/p>\n\n

In a digital sensor, some of the photosites are sensitive to BLUE, some of the photosites are sensitive to GREEN and some of the photosites are sensitive to RED.<\/p>\n\n

The association of these 3 primary colors allows to recreate ALL THE OTHER COLORS<\/strong><\/p>\n\n

The whole of the visible radiations simultaneously creates the WHITE LIGHT<\/strong><\/p>\n\n

White = Blue + Green + Red;(in equal proportion<\/em>)<\/p>\n\n

White = 1\/3 Blue + 1\/3 Green + 1\/3 Red<\/p>\n\n

If one of these thirds is a little more important, it changes the whiteness of this light, and therefore its color temperature (CT)<\/em><\/p>\n\n

And this has a direct impact on the BALANCE OF WHITES<\/strong><\/p>\n\n

BLACK = NO RADIATION VISIBLE BETWEEN 400 and 700 nm<\/strong><\/p>\n\n

The colors<\/h2>\n\n

3 fundamental primary colors = B G R (Blue Green Red) or in English RGB = Red Green Blue<\/p>\n\n

When we associate 2 primary colors, then we obtain a SECONDARY COLOR which is the COMPLEMENTARY of the absent primary.<\/p>\n\n

BLUE + GREEN = CYAN; cyan is the complementary of red<\/p>\n\n

Note: The complementary is the most different color, opposite of the primary color concerned.<\/em><\/p>\n\n

GREEN + RED = YELLOW; which is the complementary of blue<\/p>\n\n

BLUE + RED = MAGENTA; which is the complementary of green.<\/p>\n\n

2 colors are complementary when their association gives the neutral, ie WHITE \/ BLACK \/ GREY<\/p>\n\n

Ex : [B+R= MAGENTA] + V ==> B + R + V = WHITE<\/p>\n\n

==> 3 fundamental secondary colors : YELLOW – MAGENTA – CYAN<\/p>\n\n

It is with these 3 dyes, and only with these 3 that we obtain the prints or color prints.<\/p>\n\n

Color temperature<\/h2>\n\n

It is known that a white light is composed of 1\/3 of Blue, 1\/3 of Green and 1\/3 of Red<\/p>\n\n

In general, all white light sources do not scrupulously respect these proportions<\/p>\n\n

BLUE<\/strong><\/p>\n\n