Along with the new pano and HDR tools Adobe added a really neat feature in its recent release of Lightroom CC (or Lightroom 6 if you buy the standalone version). That feature was the ability to make local adjustments to filters that you have already applied, with the use of a local adjustment brush. You can do this to the graduated and radial filter tools. This brings immense controllability to these powerful tools. Before, both the graduated and radial tools were fixed shapes. The grad was rectangular and and locked to the dimensions of the image, whilst the radial tool could only create an elliptical adjustment. With the new additions, we can fine tune both. So lets have a look at how to use this new feature.
The Mask Overlay
Before we get into the nuts and bolts of using the local adjustment brush, we should take a look at the feature that enables us to use this tool. The addition of a mask overlay to both the radial and grad tools. It is very simple to enable, with the relevant filter selected in the Develop Module, go to the bottom of the image and just below, check the Show Selected Mask Overlay box. You should check this only when making local adjustments to the filter and not when initially applying the filter as you cannot see the effect on screen. Now that we know how to use this, lets have a look at making adjustments to our filters.
The Graduated Filter
In this example, I want to darken the sky a little of this shot in Bruges, Belgium. The problem is, as you can see, the spire to the left and the tower to the right will extend into the zone that the graduated filter will cover. I have added the filter to the shot, exaggerating it somewhat in order to demonstrate the power of the local adjustments. As you can see from the example, I have simply reduced the exposure and boosted clarity. The sky is much darker now but so is the tower.
To return the tower to its original density, lets switch on our Mask Overlay from the bottom. This now shows us exactly where the graduated mask is having an effect on the image.
To brush out the filter in in the tower, we go to the top of the filter adjustments on the right of the screen. There, next to Edit we see the new tool, Brush. Selecting this, you will see that the curser changes from a crosshair to a crosshair within a circle. This is the diameter of our brush size. To adjust the size of the brush, we can go to the bottom of the filter’s adjustments panel and change the size, feather and flow. Beneath the brush adjustment, there is a checkbox for Auto Mask. This will automatically find edges when using the brush. In this sample we will check this box as we have a number of straight edges within the area that we wish to change. If your shot has less defined edges, you would be better switching this off and making fine adjustments using the brush size.
With the brush size set, I am going to remove the effects of the filter in the areas that I don't want it. To do this, I simply select Erase, then brush over the these areas. As you can see, the brush removes the effect, returning the image to its original state. Once you have finished, remove the check from the Mask Overlay box to reveal the final result.
The Radial Filter
We are going to use the same image to demonstrate the radial filter adjustment. As the buidings to the left of the tower are a little dark, I am going to use the radial filter to lighten them and add some clarity.
However, as you can see, the radial brush is also effecting the sky are that we darkened with the graduated filter. Rather than actually remove the effect of the radial filter here, we are going to back the effect off, reducing the density of the filter in the sky area. The principle is almost identical to erasing the graduated filter. Again check the Mask Overlay. We then select the brush tool from the top of the radial filter adjustments panel, change our brush size and flow at the bottom but instead of clicking on erase, we select density. This is found underneath the Auto Mask checkbox. We can now set the density to a low level, in this case 10. Now when we brush over the relevant area, the effect of the filter is reduced but not removed.
The addition of the adjustment brush to these two filters is a small but highly significant step in the development of Lightroom. It increases the potential of these filters immensely from being fairly blunt instruments to being powerful, finely controllable tools.