About: http://webisa.webdatacommons.org/213597641

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	I will leave that to people smarter than I. Mind you, I suspect that there is a limit to how big an opening you can get for a given focal length, regardless, but how to arrive at that, I do not know.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com