Selective Blur in Lightroom Classic


Today’s Question: In Lightroom Classic, how can you selectively and subtly blur words in an image so they are not legible, while retaining clarity and sharpness everywhere else? Example: an image taken in a cemetery where out of respect you don’t want the names on headstones to be legible.

Tim’s Quick Answer: You can blur a specific area of a photo in Lightroom Classic with the masking feature, defining a mask for the area and then using a negative value for Sharpness to apply a blur. You can then duplicate the mask as needed to strengthen the blur effect.

More Detail: The masking feature of Lightroom Classic includes the ability to define a mask for the area you want to apply a targeted adjustment to, and then apply adjustments that only affect the area defined by the mask. To blur the area you’ve defined you can use a negative value for the Sharpness slider.

The first step would be to create a mask that defines the area you want to blur. Click on the Masking button (the dashed circle icon) on the small toolbar below the histogram on the right panel in the Develop module. Choose the type of mask you want to create based on the area you want to blur. In this case the Brush option may be best, so you can simply paint on the image to define the areas you want to blur.

Once you’ve created a mask for the area you want to blur, within the adjustment controls for the Masking feature on the right panel you can reduce the value for Sharpness. More than likely you’ll need to reduce all the way to the minimum value of -100, and even that likely won’t be strong enough.

To strengthen the blur effect, you can duplicate the mask on the Masks panel, which will duplicate both the shape of the mask as well as the adjustments applied for the mask. On the Masks panel click the ellipsis button (the three dots) to the right of the mask you created and choose the “Duplicate” command from the popup menu. Note that the name of the mask will be included with the command, such as “Duplicate Mask 1”. Depending on the nature of the area you are selectively blurring you may need to duplicate the mask several times.