One of the oldest tools in Lightroom is the graduation filter. We all know how this filter works; you drag it down and it will apply whatever settings you have dialed in.
The biggest draw-back of this tool is that it only works in straight lines. Whatever adjustments you are applying they will go across the entire line based on the orientation of line: horizontal, vertical or diagonal. This is where other tools such as the adjustment brush transcend over the graduated filter. Unlike the graduated filter, the adjustment brush gives you the freedom to be precise by painting the adjustments excatly where you want to apply them.
Where the graduated filter excels is in the speed with which you can apply your adjustments. Instead of painting in your adjustments you simply drag down your line, and the adjustment is applied. But as mentioned earlier, the adjustment filter is universal in that every part of the line will get the adjustment including areas you do not want to be adjusted.
This is especially frustrating when you are working with landscape images. Suppose you are trying to adjust the sky in your landscape image but you have mountains poking out in the horizon? In this case, the graduation filter will surely affect the mountain peaks poking sky. Problem.
Here is the solution and the tip for today. Simply go ahead and make your adjustments, don't worry if your adjustment spill to areas you don't want to adjust, then you open the secret weapon the brush. The brush tool is next to the edit button right inside the graduated filter.
When you click on it a brush menu will appear underneath the settings menu of the graduated filter
In the brush menu select erase next to the brush B button. Once you select it you will notice that your brush has a minus symbol in the middle. With this setting, you can remove the effect from all the areas of the photo you don’t want to change by simply painting over them.
There is your trick when working with the graduation filter.