Lightroom Radial Filter: The Spotlight
Updated: Aug 8
There’s a Lightroom mask called “Radial Filter” that seems like something that is of little use. There are times, however, when it is exactly what you need. Have you ever seen something that was essentially in silhouette, and you wished you had a giant spot light to illuminate it? The “Radial Filter” may be for you.
Washington Monument with a giant fake spotlight
The shot above shows my vision of the Washington Monument, although it isn’t at all what I saw while I was there. The lighting looked terrible, with the monument looking more like a black obelisk against a nearly-featureless cloudy sky. I took the shot anyway, envisioning what Lightroom post-processing magic could do with it.
This is one of those cases where I desperately needed some breathtakingly huge lighting equipment to flip the lighting ratios between the sky and the monument. Lightroom to the rescue. I don’t use it very often, but I think that the “radial filter” can sometimes be just the ticket.
If a shot calls for it, there’s nothing stopping you from using multiple radial filters, either. For this shot, though, I only wanted the Washington Monument lit up.
The starting point. A throw-away shot.
The shot above shows you what I started with. The monument was a featureless dark blob. What I wanted was essentially the opposite, where the monument was lit and the sky was darker and textured.
For my desired “spot light” effect, I’d typically adjust the global exposure of the shot at this point, so that the spot light added in later would have the desired brightness. In this case, the rest of the shot already had roughly the (low) exposure I wanted.
Make the shot really small, to make room for a big radial filter
I wanted to illuminate only the Washington Monument. I knew I could do it with the “Radial Filter”, but the size of the filter I wanted meant I needed to first really shrink the picture, using the “Zoom Level” adjustment.
After zooming, I selected the Radial Filter mask. The default settings for this filter are virtually never what is required, however.
Starting point for the Radial Filter Mask
I selected the Radial Filter mask, and made some initial guesses about what I would need. Since I was after a “spot light” effect, I clicked on “Invert Mask”. I increased the feathering, to make its effect a little more subtle. I initially set the exposure slider to +1, which I would then later adjust to taste.
Fit the radial filter to the subject
To better see the feathering effect of the filter, I went to the Tools | Adjustment Mask Overlay | Show Overlay. I left the “red” mask color, since it would show up fine in the shot.
Now, I adjusted the center, shape, and size of my overlay to be a skinny ellipse with a slight rotation to match my subject. Once the mask was set the way I wanted it, I turned off the red overlay.
Fine-tune the exposure of the subject inside the mask
Next, I scrolled up to the mask “Exposure” slider, and decided I wanted an even brighter subject. It’s easy to overdo the exposure, so be careful.
Adjust the sky: Dehaze Filter
I decided at this point that I wanted to adjust the sky and give it more drama. My two go-to choices at this point are the Nik HDR Efex Pro and the Dehaze filter. I always start by trying the Dehaze filter, since it’s really quick to try it out and later cancel it if desired. I discuss getting this Dehaze filter for older versions of Lightroom in a previous post.
In this case, I decided that the Dehaze filter was just what I needed and therefore didn’t resort to using the HDR Efex Pro plug-in.
The finished shot
You can argue all day about the honesty of using fake lighting, but I know what I like. This shot shows what I was after, and I think that the radial filter added just what was missing from the original scene.
The radial filter doesn’t just apply to landscapes. You might find that portrait lighting can be vastly improved after the fact with this same technique. As with everything, please don’t overdo it.