How many colors are there?
We see the world in color, hence the special realism and appeal of color photography, especially since modern digital cameras that shoot in color by default make it extremely accessible. Color photography not only gives us the opportunity to more fully convey the richness of the world around us, but also imposes a greater responsibility on us, forcing us to think about the impact of color on our images.
How many colors are there?
Countless number. The human eye is able to perceive electromagnetic radiation with a wavelength from 380 (purple) to 740 nm (red).
The human-visible spectrum.
This range can be divided into any number of discrete colors, although any such division will be quite conditional. Personally, I find it most convenient to think in terms of a three – color scheme-RGB.
The RGB color model implies the existence of three main colors-red( Red), green (Green) and blue (Blue), which are mixed in different proportions and give rise to a variety of color shades.
This approach is justified physiologically, since the color-sensitive receptors (cones) of the human retina contain three types of photopsins: LWS (Long Wavelength Sensitive), MWS (Middle Wavelength Sensitive) and SWS (Short Wavelength Sensitive) – sensitive to red, green and blue colors, respectively.
Like the human eye, a digital sensor equipped with a Bayer filter (and the vast majority of them) also sees the world in three colors, forming a complete color image from red, green and blue channels. Also, the matrix of a computer monitor consists of red, green, and blue sub-pixels.
The RGB model is called additive because the colors in it are formed by adding primary colors to the black color. Mixed in equal parts, they form achromatic colors, i.e. different shades of gray. The maximum intensity on all channels gives white color, and zero – black, i.e. the absence of any color.
By closing the linear spectrum, you can get a color circle, which is used for convenient representation of color transitions.
Color wheel the Color wheel. Primary and secondary colors.
The color circle is obtained when the spectrum is closed.
Colors that lie opposite each other on the color wheel, when mixed together, neutralize each other, forming shades of gray, and are called additional. Additional to the red color is blue (more precisely, blue-green or cyanide), to green – purple (crimson, Magenta), and to blue – yellow.
RGB-additive color mixing
The main colors are mixed according to the additive scheme. According to this principle works the sensors of a digital camera, computer monitor and the human eye.
It should be noted that in color printing, the image is not obtained using light, but using paints applied to a surface that can reflect light. In this case, the brightness of the color shades depends not on the intensity of the light falling on the image, but on the intensity of the light reflected from it. In this regard, instead of additive mixing of primary colors, printing uses subtractive mixing of additional colors that subtract individual spectral components from the white light falling on the paper. Obviously, subtracting the full spectrum gives a black color.
CMYK-subtractive color mixing
When printing, additional colors are mixed in a subtractive pattern.
Color characteristics and control
The main characteristics of a color are: tone (color shade), saturation, and lightness (brightness).
The tone depends, first, on the color of the lighting, and secondly, on the color of the object itself. In other words, it depends on how long the light waves will fall on the object, and on which of them it will reflect. Using the white balance settings, we can influence the color balance of the scene we are shooting within certain limits in order to achieve the maximum correspondence to reality, or, on the contrary, artificially shift the colors to suit our artistic taste.
Light control is reduced to controlling the amount and intensity of light. The more light, the lighter the colors, the less light, the darker they are. It is not always possible to influence the nature of the lighting of the scene being shot, but the amount of light that falls on the camera’s sensor can and should be controlled. The brightness of the photo depends on the will of the photographer and is determined mainly by the exposure.
The most difficult thing is to control the color saturation. For the colors in the photo to come out rich, they must be rich in life. If the original scene is colorless, you won’t be able to pull out colors in a RAW Converter or Photoshop, unless you color a dull photo manually. Yes, when colors are beautiful, there is nothing wrong with further emphasizing their beauty and intensity (within reasonable limits, of course), but faded, boring colors cannot be turned into stunning ones. You can improve them a little, make them acceptable, but no more. If you push Saturation to the limit, you will ruin the image completely rather than turn it into a masterpiece. Spend your time and effort on taking new photos, rather than resuscitating old ones. The world around us is full of colors – you only need to be able to see them.