The subject image, straight out of camera.
For a number of reasons, Lightroom's Radial Filter is my favourite tool for adding light in post-processing. The original idea behind the filter was to provide a means to create off-center vignettes in a photograph, but Adobe then incorporated all the local settings available to the Adjustment Brush and Graduated Filter (pure genius!). The filter also features an Invert Mask checkbox, which allows you to move the effect from outside of the filter to the inside. By using this with the Feather slider, you can easily use the Radial Filter as a light within your photos.
To open the Radial Filter, click on the circle icon (item A, above) in the toolstrip below the Histogram in the Develop module (or keyboard shortcut Shift+M). Double-click on “Effect” (B) near the top left side of the panel to reset all settings. Then set the Exposure to 1.00 so it's reasonably visible. Why do this now, rather than after you've drawn a filter? Because each time you make a new filter, Lightroom reverts to the settings of the previous filter, so it's best to have the settings the way you want (especially if you're creating more than one filter).
Next, select the Invert Mask button at the bottom of the panel (C) to add the effect in the middle of the filter, and set the Feather slider (D) at 50 or higher. The greater the Feather, the softer the edge of the light. Then, while pressing the Shift key, click the image and drag out a Radial Filter, as shown below. You'll instantly see an oval of light based on the size, shape, and Feather of the Radial Filter. Now it's simply a matter of dragging the filter to wherever you want to add light.
The lighting effect where the filter has been dragged out.
In the example above, I placed the filter over the rock to lighten it. By moving the cursor outside of the filter, a curved, double-edged arrow appeared and I then rotated the filter to fit over the rock. In addition to adding light, you can also boost highlights, shadows, and contrast within the filter. And if the blend isn't as smooth as you'd like, just increase the Feather slider.
The final image.
If you liked this article, Sean shares more of his wisdom in his eBook, Essential Development for Lightroom 5.
Sean McCormack is an award-winning people photographer based in Galway, Ireland, specializing in headshots and commercial, editorial fashion, and beauty/cosmetic photography. Sean's work has been used by Lucia Evans, Keith McDonald, The Conquerors, The Galway Advertiser, Galway Now, Catwalk Models, Prudence Magazine, Hot Press, and State and Trinity News. He can be found online at lightroom-blog.com and seanmcfoto.com.