Examples of Lighting - Hard and Soft Light

Uses of soft light

• Soft light use is popular in cinematography and film. 
• Cast shadow-less light
• Fill lighting. Soft light can reduce shadows without creating additional shadows.
• Make a subject appear more beautiful or youthful through making wrinkles less visible.
• Supplement the lighting from practicals. This technique is used to perform "motivated" lighting, where all light in the scene appears to come from practical light sources in the scene. Soft light does not cast shadows that would be a giveaway of a supplementary light source.

Hard light

Hard light sources cast shadows whose appearance of the shadow depends on the lighting instrument. For example, fresnel lights can be focused such that their shadows can be "cut" with crisp shadows. That is, the shadows produced will have 'harder' edges with less transition between illumination and shadow. The focused light will produce harder-edged shadows. Focusing a fresnel makes the rays of emitted light more parallel. The parallelism of these rays determines the quality of the shadows. For shadows with no transitional edge/gradient, a point light source is required.

The two images here show how diffusion of light happens differently. Basically, diffusion of light is a way of creating softer light so an image has less shadows.

 In the first image, the subject is stood outside in harsh light. There is no diffusion, hence the dark shadowing from the person. This is different in the second image; it was taken inside with a overhead light. This had a lampshade over it, which diffuses the light and makes very little shadow.

Here you can see the light changing.