I always thought that the video tutorials are the best way to learn something. I propose this very interesting video on the depth of field. And 'in English, but I could not find anything equivalently training in Italian.
[Youtube uzedefUXARE]

The sfuocatura.Questo is one of the main problems that plague digital photos.
To ensure that your photos are blurry, you should hold your camera steady in my hands, or use a tripod, if your machine it is designed. Also remember that every photo taken from a moving vehicle, will have the details blurred.

It 'also important not to get too close to the subject you are photographing (especially if it is a wild animal), or run the risk of having photos ...