I'm sure you've heard something about filters and probably had fun with some of them. That's what Photoshop users usually begin with. In my opinion, the majority of the filters are designed for rather specific tasks, so I'd like to show only the general usage principles.
1. Open your image.
First of all, let's look at the filters of Sharpen submenu. Surely no filter can really sharpen unfocused picture. However, these filters can imitate focusing of an image or selected area to a certain extent.
2. Pull down menu Filter > Sharpen > Sharpen. Look what has happened to the image. The bad thing about this filter is that it's completely automatic. To control the sharpening effect, use the filter Unsharp Mask (movies are available in the Recipes chapter).
3. Pull down Filter > Blur > Gaussian Blur... This filter blurs image or selected area numerically.
4. In the Gaussian Blur dialog box, move the Radius slider to adjust the image softness.
NB You may use the Gaussian Blur, for example, to emphasize a foreground object by blurring the image background.






More Photoshop: