Saturday, February 16, 2013

Make accurate light glows using custom gradients.

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.

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.

phlearn make accurate glows with custom gradients

Today I’m going to show you some highlights like an educated individual. Welcome to Phlearn. My name is Aaron Nace. You can follow me at Twitter @aknacer.

Today, I'm going to show you some awesome things you can do to create the highlights in your image. These are something you've never seen before and you're going to really love it.

Speaking of highlights, there are a couple of highlights from Phlearn.com. One is that we're giving away a free Phlearn pro for Beetle Beauty, that's a lot to say tomorrow in our newsletter. If you guys have not signed up for our newsletter, go to Phlearn.com slash mail or go to connect and then see the Phlearn mail, sign up for the newsletter. You'll get a free Phlearn pro tomorrow. It's going to be awesome and I can't wait for you guys to get it.

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Cool. Let's go ahead and get into this image. We got a lot to do today. I'm going to show you guys today something that's going to blow your mind.

All right, here's our image. It's from a recent photo shoot. This is our amazing model, Ricky, and very, very cool. We're going to do some behind the scenes for this, I'll talk about the lighting and things like that. Today, I want to show you guys a little about how to create some great highlights.

Before we do, I need to talk a little about the theory behind how light works, but I promise it's going to be interesting. I'm not going to make it too boring. To do so, we're going to create a new layer. I just want to zoom in a little bit and we can see a couple … this is [inaudible 00:01:43] by the way. I love shooting with stuff like that.

We can see a couple of things that I'd like to draw attention to. One is the light here on Ricky's face, and you can see the light here. That actually is from this lamp. We shot at a half a second shutter exposure, a half a second shutter speed. This is actually a really slow shutter speed. There's a strobe coming in from the camera, but this light all over here was actually from this lamp. That's not strobe light.

What I’m going to talk about is the color, the saturation and the intensity of the light on her face. We can all look at that and pretty much agree that it's orange, right? I mean that's the light color that's on her face. If you're not, it's like, "Oh well, maybe her face is orange." On a white [inaudible 00:02:27], it's still yellowish orange as well. That is the color of the light that is hitting her face.

Now let's go up here and we'll sample this light. That's pretty much white, right? There's a pretty big difference between white and orange. The reason why is, whenever you have a natural light source in your image, what you get is, the center of the light source is going to be not only the brightest, but it's going to be the least saturated as well. You're not going to have much saturation on the center of your light source. As the light source goes out and decays with the inverse square law meaning that every time you go twice the distance, you get half as much light. Every time that happens, you also get more and more saturated with your color and you change colors through the color spectrum.

What all that means and for those of you dorks out there like me, you're going to love that. What that all means is, when you're going to create a highlight for, let's say you have a light source in your light, and you know, those really nice glows you can create on lights and things like that, that everyone is a big fan of.

If you just grab white … this is what most people do by the way, when they want to create light source or like a little glow. They will paint with this color, paint with white over here and just create a glow, usually not that harsh, but they'll do something like this. The problem is, that's not how light works. We have to follow this rule that light, when closest to the source is less saturated and it also changes hue. How can we actually do this in the way that's relatively intelligent? You can do it by creating a custom gradient for your light source. Not very hard to do, actually.

Let's go to our gradient tool, you can hit "g" for your gradient tool. Up here, we're going to click on our gradient editor. For this you can just start with any old gradient, let's just start with this guy here. Now, the gradient editor here is going to go from this nice purple color to orange. If you want to change the color, just click right here on your little bucket. Click on your color and then you can just sample right from your image. You say, "Okay, I've sampled from there." Now, our end color, we'd like to be around somewhere here. Let's just go ahead and just sample, "Okay, that's what we want our end color to be."

Now, in our, let's just say, okay, we'll get back to this in a second. In our color spectrum, you're going to see if we're going to go from white to a dark orange or something like that, you tend to change a hue down your color spectrum as well. You tend to get a little bit cooler. What we're going to do is go from white, we're going to transition from yellow down into orange, because basically that's how light decays.

Let's go back into our gradient editor and then right here, we're going to choose something that's a little bit yellow. If there was a white piece of paper behind here or a medium grade piece of paper, you can actually just sample on through there because you could see that, but in this case we don't really have that.

Let's just take this color, we'll sample it something there and then click on our color there and we'll just bring it quite a bit brighter and quite a bit lighter, lighter and brighter. There we go, maybe that's a little too green. Maybe you can see something that's like, "Oh yeah, you know what? That actually does look like how light travels," which is perfect. Let's say, "Okay there," so we got light traveling through this nice yellow into this orange, there we go. And that is with our gradient.

Now, we’re actually going to use that to create a gradient over our subject. If you want to grab your radial gradient, let's just create a new layer, hit your "g" for the gradient tool, you can do something like that and create pretty much exactly something that you can't use. We're going to create a new layer and instead of using our radial gradient, we're going to choose our radial … sorry, instead of the linear gradient, we're going to choose our radial gradient.

The radial gradient, basically where you click, and drag out, you're going to see that's going to be your transition. You're going to have from one color on into another color. This is basically how light travels through your image. You can use this in many different ways to color your image. Not only that, but you can create a couple of these different guys in different types, click and drag out. Very cool.

We're going to wind up using a map as well because we don't necessarily want this orange to cover everything. That's basically the idea of what we're going to be doing.

Let's go ahead and delete that layer, let's create a new layer. I want to click inside of my light and just drag out, something like that. We've got a really nice transition here. With this, you can do quite a few different things. You can change this to something like soft light, if you wanted, which is just going to color. We can change it to something like green as well and lower your opacity. There are a lot of different things you can do.

If you want to take it a little bit step further and maybe make it a little bit smaller, take the little transform point, bring it to the center of your light, hold down the shift key and the option key and you can just make that a little bit smaller. If you wanted to make it smaller from the get-go, you can totally do that. You can see how light tends to follow a little bit more naturally if it is in fact, going from the center out.

Let's just start again. We'll just say, "Maybe, you know what, I'm going to make this a little bit smaller." Then, we'll put a layer mask on here. The layer mask you can do basically the same way. You'll go from the foreground transparent color, we're going to choose black and we're going to hit this reverse key. That's basically defines where this light stops, so let's just do that on a regular layer so you can actually see what it looks like. There we go, that's what it looks like. It's going from foreground to transparent, but I hit this reverse key so it's actually going from transparent to foreground color. If you're painting with black, it's going to go transparent to black.

That's basically how we're going to use our layer mask. We're going to go from foreground to transparent, there we go, I hit "okay." Make sure you click your … I’m realizing now this is getting incredibly complex, but the results are great, so that's really cool. You just learned something cool and fun and new about Photoshop.

Here's basically the idea. You can do this over and over again, by the way. You can just continue to [inaudible 00:08:46] it up. If you just want to hold down "command, delete" would fulfill with white which, because my background color, and do it again, you can do it again, or you can just hit "undo" making it either larger or smaller each one of these times.

What we're seeing is that instead of … let's just go ahead and compare the two. Instead of just grabbing white and going in here and painting like this, can you see how it just doesn't look natural at all? It just looks like we just took some white and [inaudible 00:09:16] there. Now what we have instead is actually something that does decay like light decay.

When you're creating a glow just like this, this is the best method to use. If you want to go through your blend mode, you can do that pretty easily. Just hit your "v" button on your keyboard, which will switch to your "move" tool, then hold the "shift" key and click the, hold down "shift" and then hit the "plus and minus." That's going to cycle through all of your blending mode. You can see some of these are going to have some interesting effects. Linear light actually looks good, I like the saturation that it's setting, but it's way too opaque, so we'll just lower the opacity of that. There we go.

Each of these ways is a really nice way to create a light glare. All right. If we do want to, let's say this is one directional, you can see that there's a side to this light, let's just paint this white, light wouldn't go out in this direction, as much as it would in that direction. I’m going to click on my layer mask, we're going to paint black at 20% flow, just over around the backside of it, just a little bit so we have something that flows out in this direction a little bit more naturally. Hold down option on your layer mask, that's what our layer mask looks like now. It still decays really well, looks great and it fits with the overall image and it follows the light, the intensity of color and light.

Thanks for watching Phlearn, guys. I hope you enjoyed your extremely dorky lesson for today on how light decays. Knowing that is going to mean you're going to be able to create some much more accurate highlights that transition across your image and won't look like they're fake any more, won't look like they're done in Photoshop.

Guys, thanks so much for watching Phlearn. I hope you enjoyed this and I will Phlearn you later. Bye everyone.

If you want to talk fast like me, you should do coke ca cola.


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