Light sources: diffused

An example of a natural single diffused light source is a cloudy day when the entire sky becomes the light source. The sun being shrouded by cloud is converted to a large source with the resultant light being even and generating either little shadow or shadows with soft edges.

In a studio, placing a semi transparent material such as a paper tissue or a translucent gel over a single spotlight or photo lamp will have the same effect. In the example the minimal shadows and lack of definition combine to make the image uniform and simplified.

Next - Direct Small Source Light