Instructions:  Drag the Focus Point above to see the direction and spread of the light in focused and flooded positions. 

Notice how the light rays are collimated (parallel) when in a focused position, similar to how direct sunlight hits the earth.  This gives a harder light quality - but because the spread is even, the light is still very smooth on the subject (unlike a direct lamp head, or a hard reflector).  When fully flooded, the light rays diverge and cross each other, widening the spread and naturally diffusing the light. This results in much softer light quality with soft shadows and less specular "punch". Being able to fine-tune and sculpt the light this way is what makes Parabolix such a powerful light shaping tool.