Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member
If in your workflow, you're starting off in Bridge with your Raw files, and you're taking them through Adobe Camera Raw, you want to make sure that you're making all of your global adjustments to tonality and to color there. But if for some reason, you're either not able to use Adobe Camera Raw or you find yourself later in Photoshop trying to make these kinds of adjustments maybe on a smaller selected area, it's important to know how they work. So let's take a look at one of the most important adjustments and that's Levels.
We're going to scoot over to Photoshop and to explain how Levels works, I'm going to create a new document and I'm just going to use the Default Photoshop Size. Then, I'm going to tap the G key to access my gradient, and make sure that I've the Linear Gradient selected. I'll also tap the D key to get my default colors. I'm going to drag a gradient from the left to the right side, while holding down the Shift key in order to draw a straight gradient. Then I'll reveal my Histogram panel by choosing Window, and then Histogram.
You can see in my Histogram that I have values going all the way across from left to right. So typically, this would be the dynamic range of the image and every image has a histogram that's unique, because the histogram is a direct correlation of the number of pixels at every color value in your image being mapped to this histogram from darks on the left to whites on the right. Let's set some color samplers inside of our image. The color samplers are nested underneath the Eyedropper tool, and they allow me to place a sampler to take a measurement of a value, in a specific location.
I'll put one on the left side here and put one on the right side. We can see on the right side, we have our values up near 255. Those are the highlights in my image and then on the left side, the values are down near 0. Now let's apply a Levels Adjustment layer to this image. On my Adjustments panel, I'll click to add the adjustment, and we can see that same histogram here as we saw in the Histogram panel. Now watch what happens when we move our black point into the right.
You can see that everything to the left of this slider is being pushed to pure black and I can see that right here in my image. In fact, if we lay down another color sampler right about here, and then we look at the measurement of our number 3 color sampler, sure enough, I've taken all those values that used to have a value of around 73, and I've remapped them all to 0. Let's switch back to the Properties panel for a minute, and I'll do the same thing with the Highlight slider. I'll move that slider into the left, you can see this whole right side of my gradient now is pure white, and sure enough, if I set down another color sampler, we can see that whatever value was 164 is now 255.
So what we need to learn from this is that if we move the Black slider or the White slider too far in on our histogram, we're going to be clipping our dark values or our light values to pure black or pure white. And that means where you used to have detail in your shadow area, you're no longer going to have detail. Likewise, where you're used to have detail in your highlights, we're going to push those to pure white. Alright, so let's close this image without saving it, and see what this looks like with a real photograph.
I'll double-click on the BlueDragon and we'll add a Levels Adjustment layer. We can see that the histogram is very different for this image. It does not cross over the entire dynamic range of the histogram. So that tells me that there are no values in this image that are being pushed to pure white. I can move this slider over to the left until it's just under the first value here that's mapped in the image, and I can do the same thing with the Black slider. What that does is it tells Photoshop to increase the dynamic range, to make sure that this photo has the black as black, and the white as white in the image and it will extend that histogram all the way from 0 to 255.
Let's go ahead and show our Histogram panel. I'm actually going to pull it out so that it's not docked. In that way, it'll just stay floating for right now and then we can toggle the Eye icon next to the Levels Adjustment layer and you can watch how the Histogram gets spread out. Right now, it's only covering this area, but when I toggle on the Adjustment layer, we have values that are extending over the entire dynamic range of the histogram. So if you hear people referring to images that look flat, that's usually because they were photographed on a less contrasty day and there aren't values that go all the way from the deepest black in the histogram to the deepest white.
Let's return back to the Properties panel for one moment, just to show you that the middle slider, that's going to change the gamma or the midpoint of your image. If I move it to the left, the image gets lighter, if I move it to the right, the image is going to get darker. And we can watch the Histogram update in the Histogram panel, as we move these slider in the Properties panel. But you should know that the Levels Adjustment layer only has this single slider to control the entire range of midtones, and as we'll see in the next lesson, we have a lot more control over those midtones, when we use a Curves Adjustment layer.
Get unlimited access to all courses for just $25/month.Become a member
164 Video lessons · 45066 Viewers
64 Video lessons · 83016 Viewers
86 Video lessons · 53227 Viewers
148 Video lessons · 90216 Viewers