Light is the essence of photography. It’s not things that we photograph, but the light they reflect. Without light, there is no photography and the way things look to us and the camera is entirely dependent on the light that reaches them.
People talk about the “quality” of light, but in fact this is a combination of different things that all light sources possess. Every light has a level, a color, a direction and can either be hard or soft. Unless you are working in a studio, where you have total control over the lighting, the first thing any photographer should do is to make an assessment of the light.
When you are making an assessment of the natural light around you, the first thing to realise is that there is never only one light source. All light travels in straight lines, until it hits something. It then bounces off. If it hits a shiny object, it will bounce at the same angle it arrived at, like a billiard ball off a cushion. If the object is matt (i.e. not shiny), it will bounce off in all directions and pick up the color of whatever it hit.
A single bare light bulb will create a hard light directly on your subject. At the same time, it creates a soft light by bouncing off the walls, floor and ceiling. The lighter those areas are, the more soft light will be created. If one of the walls was white and the others dark, then most of the soft light would come from the direction of the white wall.
As you might expect, the direction of a hard light source is much more critical than that of a soft one. In fact, changing the angle between your subject and the light source can totally transform the way it looks. If your subject has a rich texture, that can totally disappear when the light is square on to it. The more oblique the angle, the deeper the texture will appear.
For portraits, a frontal light will make people appear less wrinkled and happier. As the light moves to the side, they will look more serious. Light from above is seldom flattering and light from below makes people look downright weird. If you like landscape photography, try to visit your favorite spots at different times of the day and see for yourself the complete transformation that the angle of light makes to a photograph.
Using natural light doesn’t mean that you need to put up with bad lighting. By making a thorough assessment of the light sources around you it is possible to make the best use of what nature has presented you with.