 Introduction
'Optics' means 'pertaining to seeing' (Greek) and is also referred to as the theory of light. Because we concentrate on the motor vehicle, we are more concerned with the technical rather than the physical appearance. This
naturally includes the propagation of light, for example through reflectors, lenses and screens. This is a range of electromagnetic radiation that suits our sensitivity to vision.
Supposedly hearing loss is more detrimental to quality of life than blindness, but a healthy person would spontaneously see it the other way around. The insight that seeing is not possible without light seems trivial. It is not
the light source directly that accompanies us most, but what is illuminated by it. And the medium that the light rays have to penetrate also plays a role: the air.
In relation to the universe, we also call this air the atmosphere, which everything that comes from outside has to pass through. The sun's light rays are obviously particularly good at this, which is why it is the most important
source of light. As you can see from the fact that you shouldn't look directly into them, it's more about what reflects light. Only then do the light rays reach our eyes.
Somehow, over the course of evolution, it has specialized in this frequency range that has the strongest electromagnetic radiation from the sun and therefore penetrates the atmosphere best. Of course, light can come
directly from all possible sources. But even those that only reflect light can be perceived as light sources. On a broad day, there is basically only one source of light outside, all the others are reflections.
The different colors are also created this way. Because all the necessary frequencies for white light are present in the light of the sun, a reflecting surface, for example, only needs to block out certain ones due to its nature,
i.e. not reproduce them with the same intensity as received, and it already appears colored. If this hits the higher frequencies of light, i.e. the red color component, our eyes perceive it as a mixture of green and blue, as a kind
of turquoise (cyan). Conversely, if you subtract green and blue, you get red.
RGB color model is the key word for even the simplest programming projects, e.g. for the Internet. There you can create almost any color using #000000. The first two zeros refer to the red component, the next two to the
green component and the last to the blue component, but in hexadecimal form beyond '99' to 'FF', which corresponds to '255'. So you don't have to be satisfied with the jump from 'Red' to 'Dark Red'.
In principle, color is always the finest scattering mixture for light rays that contain all frequencies. That's why they act differently every time only certain frequencies are hit. If you shine green light on a red wall, it will turn black.
Color depends not only on the nature of the surface, but also on the light that hits it. It must already contain the frequency that is to be brought to bear on the surface.
This is easy to notice in car headlights. Simple incandescent lamps give a different light than those with halogen technology and others that are generated by LEDs or lasers. Difficult for recording devices. This is still known
from the red cast of analogue Kodak cameras. Digital cameras work here with a white balance. So you want to get the so-called color temperature under control, higher e.g. with more red content. Advertising often uses this
quite deliberately.
And since paintwork can also age, it is particularly important to test it under the same lighting conditions and even observation angles when refinishing. Color components can be hidden by scattering. When one speaks of
absorption, one only emphasizes that a certain portion has not reached the eye. Glass, generally not very absorbent, can cause what is known as light refraction due to non-parallel surfaces of light entrance and exit.
If you then throw this spectrum against a white wall, you get all the colors of the rainbow. Something like this sometimes appears in the sky under the same name, for example after a rain, which is where the name comes
from. Drivers primarily experience light scattering unpleasantly as fog, which they then try to avoid by placing headlights at a correspondingly low level.
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