Fixing Highlights and Shadows - Part 3: Shadows & Highlights Filter

In the previous part of this tutorial I presented you a technique to improve shadows and highlights using multiply and screen render modes. In this last part I want to present you a filter, which is not part of the standard Gimp distribution but which is freely available: Shadows & Highlights filter. After installing it, will be available in Filters -> Light & Shadow -> Shadows & Highlights menu.

This filter does not have the powers of its Photoshop counterpart but sometimes it may offer you nice results in a fast manner. I read a lot of critics on the Internet against this filter just because it has not preview facility. My question is: why do you need a preview? Taking in consideration how this filter works, it really makes no sense to have a preview.

When you select the Shadows & Highlight filter, this dialog is activated:



This is tricky. Why?! Because no meter what values you enter for shadows and highlights, the algorithm will do the same this. Finally you will end up with 2 extra layers, one for shadows and one for highlights, both in overlay mode (this mode works as a multiply for darken zones and as a screen for lighter ones). All these 2 sliders do is specifying the opacity of each layer, which you can of course change after running the filter, having this way the preview in the image itself.

Since there is not to much left to say about this filter here is what I've done: on the original image, after correcting the dynamic range I run this filter. On the resulting two layers I played with the opacity until I considered I got the best result: 90% opacity on "fix shadows" layer (which actually increases the highlights, recovers shadows detail) and 25% opacity on "fix highlights" layer (which actually increases the shadows, reduces the excessive light), but again feel free to experiment:


Original image:


Shadows & Highlights result:


Result from Part 2:


That's it! I really hope you enjoyed this 3 part tutorial and you found something useful in it! By the way do you not that The Gimp is completely free of cost and it runs under Linux, Mac OS X and Windows, right?

See you at the next tutorial!

Part 1: Dynamic Range
Part 2: Multiply and Screen