Join Julieanne Kost for an in-depth discussion in this video Refining dynamic range using Levels, part of Photoshop CC 2018 Essential Training: The Basics.
- [Instructor] One of the advantages of using adjustment layers is they can affect the entire image, or only a small portion. In this example, we'll make a global change to extend the dynamic range of the photo, and then add a local adjustment to the painted sign on the building. Now before I add my adjustment layer, I'm going to click on the tab for the Histogram panel and I'm going to dock it with the colors and swatches. Then from the bottom of the Layers panel, I'll select the adjustment layer icon, and choose Levels. We can see on the Properties panel that the Levels adjustment layer contains its own histogram.
The blacks are on the left, and the whites are on the right. And I can remember that by just looking at the gradient below the histogram. This histogram tells me that the dynamic range of this image is flat. There aren't any true whites and there aren't any true blacks because the histogram stops before the darkest value. If I want to increase the dynamic range of this image, so that it extends all the way from black to white, I can move the black triangle underneath the first values that are plotted.
Then, on the right hand side, I'll do the same for the whites, making sure that I don't go too far. If I click and drag further into the histogram, then I'll be clipping some of the values of my image to pure white. So I'll move that back over. If I ever want to know what values I am clipping, I can hold down the Option key as I drag these sliders and Photoshop will show me which channels are clipped first. In this case I see the yellow channel at the very lower portion of the image.
And then, as I drag over, we can see other areas. As soon as I see black in my image then I know that all three of the channels are being clipped to black. So I'm going to back off on the slider until it's just under that first value there. If we look at the histogram panel, and if I click on the exclamation mark in order to update it, we can see that there are now gaps in the histogram. And that's because we're working in eight-bit. And in eight-bit, there are set number of values in the image, and I have just stretched them out so that they reach all the way from black to white.
Well stretching them out rearranged them and it left these gaps throughout the entire histogram. That's why it's always better to work with 16-bit and make your changes in 16-bit if you can. I can also use the gray slider in the middle of my Levels adjustment layer. If I move it to the left or to the right, I can change the gamma or the midpoint of my image. So I can make it just a little bit darker, right about there.
In a later movie, we'll use the Curves adjustment layer, where we can make additional changes throughout the mid-tones of our image. But for now, we're restricted to this one slider. Now let's tap the z key in order to access the zoom tool. And I'll click once or twice in order to zoom into this sign area. Then I'll tap the l key in order to select the lasso tool. But I want the polygonal lasso tool, so I'll select it from the list.
I'll click once at the edge of the sign. Click again here at the top. Click again on the right side, down here at the bottom. And then, I'll close my selection by clicking back at the beginning when I see that round circle. With this area selected, I'll add a second levels adjustment layer. I'll click on the adjustment layer icon at the bottom of the Layers panel, and choose Levels. Photoshop automatically turns the selection into a mask for me.
And now when I darken down the sign even more, we can see that only that area is being affected, because that is the only area that is white. And a white area in a mask will show my adjustment. In order to soften the edge of the mask, so that I can't tell what has been adjusted and what hasn't, I'll click on the Mask icon, and then add a non-destructive feather by moving the feather slider over to the right. If I want to preview the before and after, I can toggle the I icon next to this adjustment layer.
If I want to restrict the adjustment layer, so that I don't I don't get that color shift, I can change the blend mode from Normal to Luminosity. And if I want to refine the adjustment, I click on the Adjustment icon in the Layers panel, make my refinements, and if I want to change Opacity, I can do so using the Opacity slider on the Layers panel. So there you go. An easy way to make changes, not only to an entire image, but to a select portion of an image, using adjustment layers in Photoshop.
Julieanne reviews the basics of digital imaging—from working with multiple images to customizing the Photoshop interface to suit your needs. She shows how to use different Photoshop tools to crop and retouch photos, while always maintaining the highest-quality output. She also demonstrates the most efficient ways to perform common tasks, including working with layers, making selections, and masking. Along the way, she shares the secrets of nondestructive editing using Smart Objects, and helps you master features such as adjustment layers, blend modes, filters, and much more—increasing your productivity every step of the way.
- Opening documents in Photoshop
- Opening files from Bridge and Lightroom
- Working with multiple documents
- Panning and zooming documents
- Customizing the Photoshop interface
- Modifying keyboard shortcuts for speed
- Understanding file formats
- Choosing color modes, bit depth, and color space
- Cropping and transforming images
- Working with layers and layer masks
- Making selections
- Removing distracting elements
- Getting to know the blend modes
- Working with adjustment layers
- Applying non-destructive filters
- Getting to know the blend modes
- Applying filters