Sharpness

If the original photograph was a little blurred (out of focus or affected by camera movement) then the GIMP can be used to make the image appear sharper. This is a very useful trick, but of course it has its limits for it cannot add detail that the original image simply does not contain. The photo below (Monte Carlo) was taken with a long focal length lens, the kind most vulnerable to camera shake.

Choose Filter>Enhance>Sharpen and then move the slider to get the best effect. You will only see the results in the preview window, not in the main image, but you can expand the preview window by dragging its bottom-right corner. Save your work.

The sharpen filter works so well that there is little point in exploring the other option: Filter>Enhance>Unsharp Mask. If you do choose to explore this filter then I suggest you start with these settings:

You may have noticed that the Filter menu also includes filters for adding blur to your pictures. This is, of course, less useful than the sharpening filter but can be successfully applied to selected background areas to concentrate attention on the main subject. We will try this in a later project.