1.3 Common Curves Corrections
Here we delve into one of the most frequent uses for Curves: enhancing the contrast of an image. This lesson provides two methods, adjusting the Curves directly and using the on-image controls.
1.3 Common Curves Corrections
[SOUND] Hello, everybody. Welcome back to Using Curves in Adobe Photoshop. In this lesson, we'll talk about the different controls and applications for using the curves adjustment panel. So, we'll start with this image here of this beautiful little girl. Now, this is a great shot, but the lighting isn't necessarily great. It could use a little boost in contrast to really bring out the highlights of her eyes, and deepen some of the shadows so we get a much more attractive photo from this. We have the curves adjustment panel already open, and we can tell from the histogram that there's not a lot of white pixels already in this image. So one of the ways we can fix that is to take this top point in this curve and slide it to the left. So, essentially, what we're saying is we're telling Photoshop to take the pixels that match up with this luminous value, this is the inputs, and force them to this luminous value. That's the output. So, we're saying take these almost white pixels and make them white. Now it's a very subtle difference there. If I pull it further over you can see exactly what that's doing. Usually, we want it to come up right against the very right edge of this histogram. Likewise with the black pixels. Right now the blacks are pretty much black. So there's not too much that we need to do there. A very common way of boosting contrast is to create what's known as the slight S curve, and that means to add a point up here towards the top right and slide it slightly left. Then add another point down here towards the bottom left and slide it slightly right. So, if you think about what that's doing in remapping the luminous values you can understand why this S curve, very subtle and slight as it is, will help increase the contrast of the image. And look at the difference as we toggle that adjustment layer on and off. Now if this feels very esoteric to you, adding points to a curve and sliding them around on top of a graph, admittedly, it's not the most intuitive way of adjusting lighting. Especially for visual and creative artists, and really would prefer to make adjustments directly on the image and not on a graph. That's why we have the on screen adjustment tool, so you engage this icon. And then as you mouse over the image you can see a little ring appear on the curve. What that is showing you is the luminous values that you're currently mousing over. So if you want to brighten up some of the mid tones, you just click and drag. And look what that did on the curve. It created a new point and it re-mapped it. Now you may not have thought to grab this mid tone point and create this curve from it working just in the curves panel, but looking over here in the image, that made a lot of sense. And you can continue working with the different tones within the image by simple clicking and dragging until you're happy with the way the image looks. And this is the result that I came up with. And I want you to take a look at the difference before the curves adjustment panel and after. Next lesson, we'll take a look at how to use some of these other controls to remove the color cast of an image.