Expert Column / Physics of lighting by Oleh Sharanevych

TREC owner, Oleh Sharanevych,  says many photographers don't understand or ignore these fundamentals. That's why they are always trying to find out from assistants the lighting of other photographers, instead of applying the physics of lighting.

1a. The larger the light source, the softer the light. 

Example: the light on an overcast day - the whole sky to the horizon - becomes one gigantic light source,  producing shadowless light. 

1b. The closer the light source, the softer the shadow

2a. The smaller the light source, the harder the light (creating strong, sharp shadow), like the bright sun overhead, the size of the sun is much smaller than we assume. If we take the tip of a pencil eraser and extend it to full arm's length, we can completely block the point of light.

2b. The further the light source, the harder the light.