The Inverse Square Law of Light Explained in Simple Terms for Photographers

If the term “inverse square law of light” immediately sets you to hyperventilating as flashbacks of college physics begin playing in your mind’s eye, take a few breaths into that paper bag, calm down, and click play on the video above.

In 6 minutes, Karl Taylor will explain this law and how it affects you specifically as a photographer without overwhelming you in the process.

In simple terms, and with a straightforward example, Taylor shows you how moving a light further away from a group of people makes it possible to properly expose everybody (both the ones closest to and ones farthest away from the light), and why we have the inverse square law of light to thank for it.



It wouldn’t do to bog down such a simple explanation with a complicated summary, and so we’ll let the video do the talking from here out. Check it out at the top and drop you feedback down below.

(via Photography Bay)

  • Leo

    I still think Mark Wallace explains it better still AND treats photographers like photographers and actually explains the physics behind the effect and how to set your studio to take advantage of the principal.

  • Jason Silzle

    Thank you Karl for the simple and to the point explanation. Demos are always a great way to share! I’m assuming the people reading this will know this but take note that the shadows do become harsher when we move our light back because effectively it becomes a “Smaller” source. Right?

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  • moonbase2

    Anyone else growing tired of people with British accents explaining the obvious to anyone with a photo degree? Maybe if I could find a way to have you imagine a British voice while you read this comment it would be better. No offense to the creator of this video, but yes, some offense.

  • Karl Taylor

    Hi Leo, what we tried to do here was keep it simple for those who are new to the concept to understand. We go a lot deeper on many other topics in lots of our other tutorials that you can find on our blog. I found in a learning environment often what you leave out is as important as what you keep in. But thanks for your feedback I’m glad you took the time to watch it, we love Mark Wallace by the way, he does some great tutorials too.

  • Karl Taylor

    Hi Moonbase2, thanks for taking the time to watch this, in our defence this video was aimed at beginners on our own channel. It was then picked up by several blogging sites, which is not something we control. The content of information we deliver to beginners is very different from that of Pros and often what you leave out as is as important as what you keep in. Please check our site to see my work and other pro level blog articles, you can find a link under my disqus profile. As for the british accent there isn’t much I can do about that, all british people come with those in the same way you come with yours. Not sure why you wanted to cause ‘some offence’ with that comment, that seems a little odd and borderline racist?

  • moonbase2

    Borderline racist? You’re a funny, funny person! My dig on the accent was an attempt to point out that every photo blog site seems to show someone from the UK spitting out novice information in a sensational way, and it gets old pretty quick. That’s all. It’s not even close to racism. I really meant no harm and this is definitely not racism, AT ALL. Keep up the good work =)

  • Leo

    Whilst I am appreciative of the content, I was only puzzled as to why the intentional removal of the math – even if it was something you added at the end or something, because the moment you add the math, you can get some really amazing practical results as in the aforementioned Mark Wallace Video.
    I just find it odd because when photographers are using lighting effects that are off camera, by that stage, they are often not shooting in Automatic and looking to learn how to shoot in P, S, A, M. But I do appreciate the point that it is for people new to the concept – but that concept is often found when a photographer starts calling themselves a photographer.
    I took your suggestion and found other tutorials valuable. Thankyou