Light has many properties that we need to learn if we want to control it and improve our photography. One of them is light falloff: the property of light to become less and less bright the further it travels from its source. Most of us know this feature as the Inverse Square Law, and it involves quite a lot of math. Well, at least too much for my taste.
If like me you also don’t really like math, you’ll love this video from Adorama. Photographer Gavin Hoey will show you what light fall off looks like in the real world, and his demonstration is visual rather than mathematical.
So, how can you incorporate your knowledge of light falloff into your photography? Well, knowing how it works can help you set up a zone with very even lighting, or with very contrasty light. I love Gavin’s thought that “photography isn’t about formulas; it’s about actually seeing what’s happening.” So, he starts off with some visual tests to show you what light falloff looks like on his studio wall at different stops. Observe how the lighting changes as his model Fern moves closer to the light source.
After visually demonstrating the light falloff, Gavin moves to actually apply it to a shot. He sets up a large black and white umbrella with a speedlight inside of it, bouncing off the white surface. The knowledge of the light falloff lets him expose the model just the way he wants: her face is properly exposed, whereas her feet and the floor of his studio remain darker, creating a high-contrast, moody shot.
Make sure to check out Gavin’s video for the visual demonstration of light falloff, as well as for some lovely shots that he made using his knowledge of this concept. And I hope that it will help you connect an image with a mathematical formula.