Light in Photography - LIGHTING - FLASH LIGHTING

Inverse Square Law

Remember the intensity of light on the subject can also be changed by moving the flash head or light closer to increase the intensity or further away to reduce it. If the unit is moved twice the distance away from the subject, the amount o flight reaching the subject is not 1/2, but 1/4 or two stops. This is why it is impossible to use an on camera flash to illuminate a sports event like the olympics from the stand, the distance is too great and by the time the light has reached the athlete the power has diminished to the point where there is little effect.
If we use a flash with our camera out doors, we find the light falls off dramatically as the distance increase. We can se in this image how the foreground is over exposed while the tree in the background sits against a black ground.
Here is another example with more light falling onto the tree
.In this example we can see the warm tungsten light from behind Rodan's thinker falling off.	Mouse over
	In this image we can see how both the intensity of the blue light coming in the window falls off and the yellow tungsten light on the floor falls off as it projects up the wall.

Want to learn more? - do a workshop or one on one with Lloyd Godman