§ 1. Open "focusing.jpg" file from our sample folder and set the magnification level to 100%. As you can see, the bird is badly blurred.
§ 2. Surely, no program can bring it into focus. However, some tools can imitate sharpening. From the program menu, select "Filter > Sharpen > Sharpen". The command has been applied. Scrutinize the image and estimate the effect. Well, perhaps with a better image this method might do...
§ 3. The bad thing about the tested command is that it is completely automatic. To control the sharpening settings, pull down "Filter > Sharpen > Unsharp Mask". In the "Unsharp Mask" dialog, strengthen sharpening effect by moving the Amount and Radius sliders. Then slightly increase Threshold to reduce noise caused by sharpening.
§ 4. It may sound strange, but reducing sharpness is even more frequent operation in our course. From the program menu select "Filter > Blur > Gaussian Blur". Then in the "Gaussian blur" dialog, set Radius value to adjust the softening effect.
§ 5. Very often we have to increase sharpness in a particular area without affecting the rest of the image. To achieve this, activate the Sharpen Tool. In the Options bar, adjust the tip size, the tool's strength, and other parameters. Then paint on the image area you want to sharpen.
§ 6. Similarly, to soften a specific area, choose from the Toolbox the Blur Tool, set it options, and paint on the area you want to blur.
NB The Sharpen and Blur tools are hardly suitable for extensive corrections. More advanced techniques for sharpening and blurring of a certain image area with controllable parameters (for example, sharpening the bird and softening the background) will be explained later on.