About: http://webisa.webdatacommons.org/228214590

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	In the case of the use of lens as the common means of converging signal and control lights, strictly speaking, there is a problem that focal length differs according to wavelength, but this is not a problem with concave lenses.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com