Very often, outdoor photography involves the pursuit of pictures that are sharp front to back. Sometimes, however, you’ll want photos with blurred backgrounds. This helps isolate your subject, and can look very cool in the right circumstances. It is common practice (or at least it should be) when it comes to including people and wildlife in your photos. It is also useful when there is a defined subject you want to highlight.
We already have an article on achieving a shallow depth of field, but here is an additional video tutorial as well.