Summary: Lighting angle reveals form in a three-dimensional object. To see how light from a particular angle will affect your subject, view the subject from the position of the light.
We live in a world of off-axis light. The sun does not stay right behind us. Our lighting fixtures at home illuminate us from above and other various angles. And we are constantly exposed to imagery - both still and moving - that makes use of very sophisticated off-camera lighting techniques.
Yet so many photographers, when they take the time to compose and illuminate their photos, settle for the bland, flat, on-axis (i.e., on-camera) light. Because that is the path of least resistance.
The biggest failing of on-camera flash is that the light, which comes from a point very near to the camera's optical axis, does not have the ability to reveal the three-dimensional quality of the subject.
Granted, most flashes can be tilted to bounce the light off of walls or ceilings while still attached to the camera. But those are very limited choices out of a wide variety of lighting angles available to the off-camera lighting designer
very interesting post from strobist.com ... i love this place.
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