About: http://webisa.webdatacommons.org/82012772

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	If memory serves me correctly, there was an optical diagram of a 50mm f1.4 lens, and how focus shift occurs as the lens aperture changes.
http://www.w3.org/ns/prov#wasQuotedFrom	typepad.com