Jan 31, 2013

Make accurate light glows using custom gradients.

Light Falloff

In this episode we discuss something that sounds extremely boring but is actually quite interesting: Light Falloff. A lot of people know that light decreases in intensity as it travels further from a light source, but at the same time it increases in saturation and changes hue.

This is important because when you are enhancing the light that falls on your images, you have to take these properties into account or you will wind up with something that doesn’t look accurate.

I wasn’t born with this knowledge, I had to learn it somewhere. To learn more about how light works with photography, check out Light Science and Magic.

Working with Gradients

To make these transitions easier we show you how to build a custom radial gradient in photoshop and use that to control how light falls. We also cover creating a special gradient that is perfect for creating a layer mask for ultimate control of your light source.

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  • user image

    Thanks for the tip on the book.. I just finished the E-myth recommended by this site and it was a great read, look forward to reading light science and magic.

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    Jay Stebbins


    This was a fantastic tutorial on light and it’s properties and how to manipulate them in Photoshop. Heading to check out the Light, Science and Magic book now.

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    Chris Fore

    Absolutely loved this video Aaron. Thanks so much! Keep the Lighting Science coming. I already ordered the book…you should get a cut for the shout out.

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    Claus Olsen

    Excellent episode. How do you know to use yellow to go from white to orange? What do you do if the light was a different color?
    And btw, you got the inverse square law wrong: When you double the distance you don’t get half as much light – you “only” get a quarter of the light. You probably know this and simply misspoke 😉

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      Aaron Nace

      You are totally right Claus, I misspoke 🙂
      As far as the hue shift goes, I am regurgitating knowledge I have read. Not sure the physics behind it.

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    Andrew Nguyen

    Thanks Aaron for once again a great episode!! You have taught me so much!!

  • user image

    Why did you put a gradient that mirrored the one that was already there?
    . perhaps do it from the opposite side to balance?

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    Gabriel Tompkins

    Excellent tutorial as always, Aaron. This is one of the best explanations of gradients and their practical usefulness for photographers. They’re used by designers all the time, but probably underutilized and overlooked by many for image post processing. One minor correction on inverse square law, though. It’s actually 1/4 the amount of light at twice the distance. 😉

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    Lise Yijing

    A transcript! GREAT! Thanks, and I speak for all non-english speakers.
    Plus: a great video. Thanks for that as well.

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    Christoffer Rosenfeldt

    This tutorial helped me SO much in creating this image. I cannot express my gratitude to you guys for helping me out and teaching me as much as you have. I’m just sorry I didn’t know about Phlearn sooner! Aaron, you’re amazing.