What is light quality? What is direct light, scattered light, and reflected light?

The texture of light is a kind of visual and psychological perception of light. Soft or hard is used to describe certain properties of light. Different light sources have different light textures, and the same light source has different light quality due to different illumination conditions (such as medium and propagation direction). Different light quality will make the photographic picture form different soft and hard tones. According to the different light quality, light is divided into three types: direct light, ‘scattered light and reflected light. The light from the same light source will be refracted, reflected, transmitted, and scattered when propagating in different media.

Direct light: also known as hard light. Light traveling in a straight line. Direct light can be natural light or artificial light, that is, sunny sunlight and straight-line artificial light (electronic flash, spotlight). Direct light has high brightness and hard light quality. The irradiation direction is obvious, which can produce thick shadows. The object's light-receiving surface has a large contrast with the shadow surface, with clear edges and strong light perception. Images taken with direct light have hard tone, high contrast, lack of intermediate transition levels, clear outline of the subject, and strong three-dimensionality. Use more main lighting indoors, and it is advisable to shoot hard-tuned works, such as men and elderly people.

Scattered light: also known as diffuse light, soft light. Light whose propagation direction is not obvious. The scattered light can be natural light or artificial light (such as soft light). Direct light is diffused by non-directional refraction and reflection through media such as water vapor, smoke, dust, gauze (such as diffuser), glass, and water (such as underwater photography) during the propagation process. There are mainly cloudy, cloud, fog, rain, snow, sky light and soft light during twilight. The bright sky before sunrise and sunset is the scattered light from the weather medium. The scattered light has low visibility and soft light quality. The illumination direction is not obvious, and no obvious projection can be produced. Objects receive uniform light, with unclear edges and weak light perception. The images taken with scattered light have soft and delicate tones, low contrast, low sharpness, lack of clear outline of the subject, and weak three-dimensional effect. Use auxiliary light more indoors, and it is advisable to shoot soft-tone works such as women, children, hazy films, and lyrical films.

Reflected light: The light reflected from the light-receiving surface of the light source shining on a reflective object. The reflected light can be natural light or artificial light. Reflected light has two meanings: First, the reflected light of the subject. Reflected light can show the color of the object. If you are not directly shooting the light source, the reflected light of the object is used to shoot any scene; second, the reflected light of the subject is illuminated. The light from the light source shines on the A object, and the reflected light from the A object (such as the reflector, also known as the second light source) shines on the B object, and the B object is the subject. Reflected light Direct light illuminates the uneven surface of the object, and the reflected light has scattering properties.

The light quality of the reflected light is closely related to the color and texture of the reflector. The reflectivity of white objects can reach 90%. The reflectivity of black objects is about 10%. The reflectance of medium gray objects is about 18%. The reflected light is less likely to be used as the main light and is mainly used as a supplementary light. The reflectivity of an object is closely related to the color of the object and the smoothness of the surface of the object. There are no pure white objects with 100% reflectance and pure black objects with 0 reflectance in nature.