Cinematography Documentary

(With some weird cutting thing at the end which removed focus related clips- see below for vocabulary).  Thanks to Sarah for helping me film it).
Deep Focus- a technique using a large depth of field.   In deep focus the foreground, middle ground and background are all in focus

Shallow Focus- in shallow focus, one plane of the image is in focus while the rest is out of focus.   It is typically used to emphasise one thing over another

Focus Pulls- this is where you change focus during the shot