When we talk about photo retouching, we talk about details and flaws that can be very easily omitted after spending a few hours working on a single image. That’s why we need a special technique to take care of this problem.
A Solar Curve is a wild curve with a very regular wave pattern which is supposed to push the color information so much that it exposes parts of the image that you don’t normally see.
To create a Solar curve, click on Curves Adjustment Layer and add 6 equidistant points. Now drag the first point to 100%, the second to 0% and so on. Try to replicate the settings from the above image as close as possible but don’t stress too much over it as there’s no need to make an identical arrangement.
This will give a really strange look to your image but it will also accentuate the highlights, shadows and midtones, in order to reveal things that are normally hidden or don’t match. People started calling these things Solar Curves because they can make an image seem solarized, but that’s not really what they’re used for.
The biggest benefit of using this technique is that it makes the retouching mistakes very apparent. Besides that, will help you to expose things like lens dust, patterns, or irregularities that can be found in very dark or very light areas.
Place your Solar Curve on top of the other layers, and now you can retouch below it by setting the Clone Tool or the Healing Brush Tool to Current & Below. This way, the curve won’t affect your work.
If you’re using it on beauty images (as I did in the above image), do not strive to make perfect transitions behind the solar curve. This will make the skin look too smooth and you’ll end up with an overdone retouch. It’s a good practice to temporarily disable the solar curve from time to time and check how your image looks like without this filter.
Once you’ll get used to the bizarre colors, you’ll find it very easy to work your imperfection out.
> Add it above skin layers. It really enhances the blemishes.
> Add it above a restoration to find missing details.
> Add it above cloning to check for variations.
> Add it as a final step to check banding on gradients.