I’ve seen several beautiful photos recently that were nearly ruined by the fact that sharpening produced halos where sky met edges. What’s worse, the photographer could have easily removed them in Photoshop. With less than a minute of work, those halos could be gone.
Here’s an example that illustrates what I mean.
I made this photo of a rock climber in Arches National Park. It’s a nice photo but if you zoom in, you will see the halos I’m writing about.
After sharpening the image, I was left with a halo around the edges.
Wouldn’t it be nice if you could simply take the clone stamp, select from the sky and paint the halo out, without affecting the rock? The good news is that’s exactly what you do. To get rid of those halos, (make sure you are working on a flattened or composite of your image) you simply change the blend mode of the clone stamp from Normal to Darken. The Darken blend mode tells Photoshop to replace pixels that are lighter than the selected area with pixels from the selected area BUT, only replace pixels that are lighter than the selected area. So long as the selected area is lighter than the adjacent rock, only the halo will be replaced.
Notice how the halo disappears without leaving any telltale signs on the rock. Brush size doesn’t matter, just make sure that opacity is set to 100%.
Unless you are very careful, your cloning can leave you with areas where the sky doesn’t match properly like in the image below.
To prevent this potential issue, you can use a little different approach to removing halos. Instead of working on a flattened or composited image, add a new layer. Click on the new layer icon at the bottom of the layers palette:
Change the blend mode of the layer to Darken and use the clone stamp to eliminate the halo. (It doesn’t matter what the blend mode of the clone tool is.) If you get mismatching sky, fix it using a gaussian blur. Make sure the new layer is selected, click on Filter >> Blur >>; Gaussian Blur and apply enough blur to fix the problem. The blur will only be applied to the layer you were working on. It, of course, will only have the data from fixing the halo so you won’t cause yourself any other problems with the image.
Halos can ruin an otherwise great photo. Fix them quickly and easily in Photoshop.