About: http://webisa.webdatacommons.org/446044275

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 you didn't want to use the shutter, there was an option for releasing the spring tension and leaving it open for ground glass use.
http://www.w3.org/ns/prov#wasQuotedFrom	largeformatphotography.info