In the latest release of Lightroom - the Classic version - and Adobe Camera Raw, there is a new feature that is certainly worth a look. It's called Range Masking. If you've ever wanted to bring down the tone of the sky but find that a gradient tool darkens trees or building that rise above your horizon, then this feature is for you.
Range masking is a feature of the local adjustment tools that will allow you to limit the adjustment to a range of colors or tones in your image. You'll find Range Masking in both Lightroom Classic and Adobe Camera Raw. As a part of the local adjustment tool, these adjustments are completely non-destructive and can be edited later on.
In the image above of Lake Moraine in the Canadian Rockies, a common tool that may be used to adjust the sky is the gradient tool. Unfortunately, when that tool is applied to an image like this, you often darken the trees that are sticking up into the sky. Meet our new Range Masking feature.
You can apply a gradient adjustment to the image and then turn on the Range Mask feature at the bottom of the graduated filter panel. You'll notice that Range Masking can be applied using luminance or color.
For the image above, we'll select the luminance option. You then adjust the range with two sliders.
The slider on the left, by default, is set at zero (0). This is the shadow end of the image. At 100 you see the highlight slider. With such a bright sky, I want to leave the highlight slider where it is. I then move the shadow slider to define the range of luminance values that I want to adjust with the tool.
Finally, there is a smoothness slider to help define the transition in your mask. When you set it to zero you have an abrupt, "hard edge" mask. As you move to further to the right, the mask edge becomes softer. And, as with most edits with masks, you'll find the softer edges will give you better results.
If you want to see the mask that you're creating, just hold down the Alt key as you adjust the smoothness slider.
For some images, it's best to select the mask using a range of colors. In the case of our flower photo, we can select the bright color of the flower petals and apply any local adjustment that will make the flower pop. You may want to apply saturation or clarity. It's up to you.
When selecting colors, you may find it better to select a range of colors with the eyedropper. To do this, click and drag the eyedropper to include a range of the subtle hue changes in the petals. Don't forget, you can always view the mask you're creating by holding the Alt/Option key while you make the adjustment.
Another technique is to use the Shift + Click with the eyedropper to add multiple samples in your selection. Like any of the tools, you just have to practice and learn how these tools respond. You'll soon find what works for you.