When you adjust levels, you're adjusting these different tones. And while you could use the brightness and contrast tools for a similar type of adjustment, they're much less powerful than levels. There are many reasons to use a levels adjustment.
For instance, if you have a particularly dark—or underexposed —image, you might want to make the midtones and highlights brighter while keeping the shadows relatively dark. You can see an example of this in the images below. If you've never adjusted levels before, this tool may feel a little unintuitive at first. At this stage, the most important thing is to practice making different adjustments.
As you start to gain more experience, you'll be able to use it more effectively. And remember, if an adjustment doesn't look right, you can always undo your changes and start over. Click and drag each of the Input Levels sliders in the Properties panel to see the effect.
Try to find the settings that look best for this image. Review our lesson on reading a histogram to learn more about what it can tell you about an image. If you move the white slider too far to the left, you'll begin to lose detail in your image. This is known as clipping. In the image below, you can see that the clouds have lost a lot of detail, and the color of the sky has also changed.
Both of these problems are caused by clipping. If you move the black slider too far to the right, you'll start to see clipping in the image's shadows.
In this example, the bird and branches have lost almost all of their detail. The color of the sky has also changed to a darker blue:. Remember, because you're using adjustment layers none of these changes are permanent until you export your image.
So if you see any clipping in your image, don't panic! Simply look at your adjustment layers to find the source of the clipping, then readjust the levels as needed. Note that the histogram will be unique for every image. If an image has the proper exposure, the histogram will be complete, with no data missing.
In a case like this, a colour cast is something you want to get rid of. If however you have shot a summer sunset and the whole scene is bathed in warm orange light, this could also be seen as a colour cast, but in that case you would probably not want change it.
One way to find colour casts in your images is to look at an area of the image that should be white and see if it has a tint. A colour cast will vary depending on the light you shot under; it could be green, magenta, blue, yellow, orange, or anything in between. You can use the Levels tool on any image that needs the colour or contrast corrected. If you have an image that needs to have the colour cast corrected, like my shot of the Star Wars Stormtrooper does, then do the following:.
If your image has a colour cast the example image does, as there is a slight blue colour because it was overcast weather that day , follow these steps. If you do have a colour cast in your image, then do the following:. Bring the white and black sliders to the point where the graph starts moving upward.
Part 1: In the levels tool, click on the drop down box above the histogram that says RGB. This will open up the three channels individually. Click on RED and bring the white slider and black slider in to part of the histogram where it starts to move upwards.
This step will only work if there is a colour cast in your image. If there is no colour cast, the histogram will spread to the edges of the graph. The red areas in the screenshot above show you where there was no colour information. By sliding the sliders inward to the edge of the graph, you will start to neutralize the colour cast.
I'll drag it down to 0. And here's the "before and after" comparison of what's happened. The original gradient without any midtone adjustments is on the bottom and the adjusted version is on the top. Once again, the midtone slider had no effect on the black and white points, but the tones in between now appear darker. Again, this seems like the opposite of what you might expect. Dragging the midtone slider towards white feels like it should be lightening the midtones, when in fact, it darkens them.
It's easy to get things mixed up with the midtone slider, so if you ever find yourself dragging it in the wrong direction, just stop, drag it in the opposite direction and say to the person looking over your shoulder, "Just checking to see if you're paying attention":. Now that we've covered the details of how Photoshop's Levels adjustment works, let's take everything we've learned and use it to quickly improve the tonal range of an image.
Here's an old photo I've scanned into Photoshop. The image has faded over time and is now suffering from low contrast due to a lack of any real shadows or highlights. Even though I'll be correcting a black and white image here, you can use the exact same steps with full color images:.
Using the same steps we covered earlier, since I'll be applying Levels as a static adjustment, the first thing I'll do is make a copy of the Background layer. Photoshop makes the copy, names it "Layer 1" and places it above the Background layer:. Since it's always good to give layers descriptive names, I'll quickly double-click on the new layer's name "Layer 1" and change it to "Levels". We now have our copy of the image to work on so we're not making changes to the original:. To add a Levels adjustment, I'll go up to the Image menu, choose Adjustments , and then choose Levels.
Either way opens the Levels dialog box:. I'll zoom in on the histogram, and just like with the gradient we looked at earlier, this histogram is showing us that we currently have no black or white pixels in the image. The left side of the gradient starts at a lighter than black shade of gray and the right side starts at a darker than white shade of gray. We have no detail at all in the darkest and lightest tones, which explains why the photo is lacking contrast:.
As we've learned, there's three simple steps to correcting this image. First, we set a new black point. Second, we set a new white point.
And third, we lighten or darken the midtones as needed. I'll start with the black point by clicking on the black point slider and dragging it over to where the left edge of the histogram begins. Notice that the black point value in the box on the left increases from 0 to a level of This means Photoshop is going to take all the pixels that were originally at brightness level 42 and darken them to level 0, making them black:. Here's the photo after setting the new black point.
Already, things are looking better with deep, dark blacks and lots of detail in the shadows:. Next, I'll click on the white point slider and drag it over to where the right edge of the histogram begins. If you look closely, you'll see that the histogram is showing a few pixels just before the steep rise in the histogram, but I'm not going to worry about those. Instead, I'll drag the white point slider right up to where the bulk of the histogram begins. Notice that the white point value in the box on the right has decreased from level to level Photoshop will take all the pixels that were originally at level and brighten them to level , making them white:.
And here's the result. We've now corrected both the shadows and the highlights, giving the image a much needed boost in contrast:. We've adjusted the black point and the white point, but now the image is looking too dark overall. To fix that, all we need to do is lighten the midtones, and I can do that by clicking on the midtone slider and dragging it towards the left.
Small increases or decreases in the midtone value can make a big difference, so in most cases, you won't need to drag the slider very far. Here, I've increased the midtone value from it's default of 1.
Unlike setting the black point and white point where it's easy to see where the left and right edges of the histogram begin, the midtones are a bit more subjective. You really need to keep an eye on the image as you drag the midtone slider and decide for yourself which setting looks best:. Here's a couple of quick tips when working with Levels.
If, at any time, you want to compare your adjustments with how the image looked originally, simply uncheck the Preview option in the dialog box. With Preview unchecked, you'll see your original, uncorrected photo in the main document area.
Click inside the checkbox again to turn the Preview option back on and view your adjusted version. You can also toggle the Preview option on and off by pressing the letter P on your keyboard:. This will change the Cancel button into a Reset button. Click the Reset button to reset the sliders:.
When you're happy with your adjustments, click OK in the Levels dialog box to commit them to the layer and close out of the Levels dialog box if you want to close out of the dialog box without applying your settings, click Cancel instead :.
Once you've applied your settings, you can compare your adjusted version of the image with the original by clicking the visibility icon the eyeball icon for the Levels layer in the Layers panel:. Clicking the visibility icon once will temporary hide the Levels layer in the document, revealing the original, uncorrected image:. And there we have it! In this tutorial, we covered the basics of how Photoshop's Levels adjustment works and how to apply it as a static adjustment to correct overall tonal problems in the shadows, highlights and midtones of an image.
Yet there's still more to learn! Therefore, the midtone slider's main use is to brighten or darken the midtones within an image. When else should one use the midtone slider? Consider the following scenario: your image should contain full black and white, and even though the histogram extends to full black, it does not extend to white.
If you move the white point slider so that it reaches the edge of the histogram, you end up making the image much brighter and overexposed. Using the midtone slider in conjunction with the white point slider can help you maintain the brightness in the rest of your image, while still stretching the highlights to white:.
Note how the sky became more pronounced, even though the overall brightness of the image remained similar. If the midtones tool were not used, the image to the right would have appeared very overexposed. The same method could be used to darken the shadows while maintaining midtones, except the midtones slider would instead be moved to the left. Note: Even though the midtones slider is always initially at , it is instead shown as 1.
This way, the midtones slider is always at 1. The midtone "Input Level" number actually represents the gamma adjustment, which can be thought of as a relative measure of the number of levels on the sliders left to those on its right.
Thus, values greater than one mean there are more levels are to the slider's right, whereas values less than one mean more levels are to its left. One can use the dropper tools on the far left and right to set the black and white points by clicking on locations within the image that should be either black or white, respectively. This is often not as precise as using the sliders, because one does not necessarily know whether clicking on a given point will clip the histogram.
The black and white point droppers are more useful for computer-generated graphics as opposed to photos.
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