Frequency separation is a powerful technique. Photographers think of frequency separation as a skin retouching tool, but it is so much more. I often use use frequency separation for retouching backgrounds. Affinity Photo includes frequency separation built right in which is convenient. In this retouching walk through, I show you how to use it to fix sections of the background in a natural way.
About the Photo Shoot
One of my upcoming brides was brave and embraced the idea of an underwater bridal session. We took over a friends pool and started shooting. Underwater photography adds a large number of complications. Most water, even the cleanest, isn’t really that clean. There are always particles of dust and grit floating around. When you toss in a model, a photographer, a background and a bunch of other stuff and then swim around, the water gets murky quickly.
I always try to be as close to the model as I can when shooting under water. We were shooting on a 16-35mm lens and I was zoomed all the way out to 16mm. This creates distortion but that is a trade off I accept. It also brings in a lot of background I’d like to avoid.
Even with our 15′ wide black muslin backdrop, the sides of the pool were visible. They broke the mood of the photo. It takes the viewer out of a mysterious situation and puts them into a pool. That isn’t what I wanted. Therefore, I retouched the image to remove the unwanted visible pool on the edges.
Frequency Separation for Retouching Backgrounds
Frequency separation separates high frequency changes (small details) from low frequency changes (the overall tone and hue of areas of the image). By separating out details, you can work independently on different aspects of the image.
In this image I needed to alter the background to remove the obvious sections of pool wall. Because the mid-ground had a lot of fine details, such as the flecks lit up in the water, simple cloning or in painting would be a nightmare. With frequency separation, I was able to work independently on the background tone and hue without having to worry about the fore and mid-ground water.
Before and After
The differences are subtle and in the dark corners. And to my eye they make the image much better.