Softening Effect
In this very simple tutorial I’ll show you how to soften an image in GIMP. This effect is very similar to the effect you might achieve when using a Softening Filter.
Using Gradients for Photos
In this very simple tutorial I’ll show you how to achieve a very similar Neural Density Filter (N.D Filter) effect to your photographs by using gradients in GIMP.
This method is no substitute for the real filter that you put on your lens, but if you’d like to enhance a very flat/bland shot that you’ve already taken, then this is a good start.