What Photographers Should Know About Light Fall-Off

No matter what sort of lighting you are interested in, the subjects you photograph, or the equipment you are using, there are certain physical properties inherent to all light that are crucial to understand if you want to take better creative control of your images. Light fall-off is one of those properties, and this fantastic video tutorial will show you how it works and how to leverage it for better images. 

Coming to you from Gavin Hoey with Adorama, this excellent video will teach you everything you need to know about light fall-off. We all know that the brightness of a light gets lower and lower as you move farther away from a source, but that decrease is not linear with distance, but rather varies with the square of the distance. Humans are notoriously bad at estimating non-linear phenomena, and as such, it is important to gain an understanding of fall-off and how it affects your work, particularly how you can use it to control contrast or to evenly illuminate large groups. Check out the video above for the full rundown from Hoey. 

If you would like to continue learning about lighting fall-off and other properties of lighting, be sure to check out "Illuminating The Face: Lighting for Headshots and Portraits With Peter Hurley!"

Alex Cooke's picture

Alex Cooke is a Cleveland-based portrait, events, and landscape photographer. He holds an M.S. in Applied Mathematics and a doctorate in Music Composition. He is also an avid equestrian.

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4 Comments

Thanks for sharing. It's very much appreciated.

Light diminishes with the square of the distance — period. Understanding becomes easier by using for example: 1.4' - 2' - 4' - 5.6' - 8' - 11' - 16' - etc. These numbers should sound familar they are simply the ƒ-stops on a lens each whole stop is the multiple or divider of the square root of the number two (2) 1.414. A light 4 feet away from the subject, the lens needs to be opened three full stops with the same light 11 feet away, or closed down the closer you bring the light using the ƒ-stops as your subject to light distance. Same principal for any light. When checking out the guide number for your "wink flash," use 11 feet away. For studio strobes, it's better to use a flash meter.

love all of gavin's tutorials

Great demo. Really well explained