Inverse square law
It is not superfluous to mention here also the law of inverse squares, the action of which you will certainly encounter. It sounds like this: the intensity of light is inversely proportional to the square of the distance from its source. This means that if the distance from the light source is doubled, the illumination of an object will fall fourfold. This is a lot – two stages of exposure. Our vision adapts to changes in light, and the difference in two steps will not be too noticeable to the eye. In the photo, it will become obvious.
Imagine that three people are sitting in a room by the light of a table lamp. One of them is a meter away from the lamp, the other is two meters away, and the third is three meters away. According to the law of inverse squares, the second person will receive four times, and the third – nine times less light than the first, and, therefore, to make a good group portrait without additional illumination will be difficult.
Direct sunlight does not fall under the law of inverse squares, again due to the large distance to the sun. No matter how you move the subject on the surface of our small planet, the changes in its distance from the sun will be negligible.
So which light is better?
Good question! The best light is the one that you understand and know how to use for your own benefit. Light is the physical basis of photography, and it is also its artistic basis. Learn to see light, analyze it, compare it with your creative idea and modify it according to it, and if this is not possible, do not hesitate to change the subject and even your entire shooting schedule in accordance with the available light. Any type of lighting has more or less photographic potential, the only difference is in the area where it can be used successfully, and in the convenience of its use. The higher the level of skill of the photographer, the wider his creative horizons. A good photographer on the one hand is more selective in choosing the optimal lighting, and on the other-better copes with the difficulties that non-optimal lighting creates.