Przecież to jest opisane we właściwych żródłach:
http://www.state.gov/documents/organization/87206.pdf
9 FAM 41.31 N11.6 Still Photographers
(CT:VISA-701; 02-15-2005)
The Department of Homeland Security (DHS) permits still photographers to enter the United States with B-1 visas for the purpose of taking photographs, provided that they receive no income from a U.S. source.