Shallow depth of field look with a rack focus effect
Using Advanced Masking Tools 2, we isolated the fountain and blurred the background (by setting the "Outside.Opacity" to 100 and the "Outside.Blur" to 20). We then keyframed the blur to shift from the background (the museum) to the foreground (the fountain) to simulate a rack focusing effect that cameras with manual focus controls are capable of.
Using footage we shot for this purpose on a tripod, we split the clip into three clips: girl on right, girl in middle, girl on left, and no girl (our clean plate). On the clips with the girl, we masked around where she was so that the other layers underneath would be visible. After adding some feathering and minor exposure adjustments, we bundled all four clips into a compound clip and added the Shaky Cam plugin to help make it more realistic.