If the original photograph was a little blurred (out of focus or affected by camera movement) then Photoshop 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>Sharpen (renforcement in French) and then experiment with the 4 different options. I recommend that you use Sharpen (plus net) or Sharpen More (encore plus net) rather than Sharpen Edges (contours). You may need to apply the sharpen operation more than once in order to get a good result. Try deliberately applying too much sharpening and notice how the image takes on an harsh and ugly character. (Don't forget you can always undo several steps using the History window from the Window menu.) The Unsharp Mask (accentuation) is a complex tool probably best left to the professionals - if you want to experiment with it then I suggest you use a high setting for amount and low settings for radius and threshold. See the help system for more. Save your image when done.

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.