Today’s Question: There are occasions in Lightroom when I would like to erase a portion of a radial filter adjustment that I am attempting. This would allow more detailed shaping to the effect than just tugging on the adjustment points of the standard tool. Is this possible somehow?
Tim’s Quick Answer: You can indeed combine the basic effect of the Adjustment Brush and the Radial (or Graduated) Filter in terms of which areas of the image are affected by a targeted adjustment. Just keep in mind that there are some challenges in terms of your flexibility in refining the definition of the portion of the image being affected.
More Detail: When you use the Radial Filter, the Graduated Filter, or the Adjustment Brush within Lightroom’s Develop module, you’re essentially defining two attributes related to a targeted adjustment. First, you’re defining the area of the image being affected by the targeted adjustment. Second, you’re defining the actual adjustment you want to apply to that area.
Lightroom 6/CC allows you to combine the effect of the Adjustment Brush with either the Graduated Filter and the Radial Filter. The first step is to define the overall shape of your targeted adjustment using either the Graduated Filter or the Radial Filter. You can then use the Brush option at the top of the panel for the Graduated Filter or Radial Filter adjustments to effectively work with the Adjustment Brush while you’re using one of these two filters.
With the Brush option, just like with the Adjustment Brush, you have the option for an “A” brush or a “B” brush, as well as an Erase brush. So you can erase portions of the mask that defines the area being affected by your targeted adjustment, and the “A” or “B” brush to add portions to the mask.
So, for example, if you want to apply an adjustment to the central area of the image using the Radial Filter, but then also apply the same adjustment to additional areas of the photo, you could draw an ellipse with the Radial Filter tool and then use the Erase option for the Brush to paint the adjustment into additional areas of the photo.
The big challenge comes with making changes to an existing Graduated or Radial adjustment after you’ve used the Brush option. If you were to, for example, move the Graduated or Radial shape after performing some painting with the Brush option, the brush strokes will no longer align in the same way with the existing shape you had created.
Based on these limitations, my recommendation is to start with either the Graduated Filter or the Radial Filter, and to get that shape as close to perfect as possible before working with the Brush option. Then fine-tune with the Brush option as needed, and of course refine the overall adjustment effects as well.