Not tried their sound trigger ,don't think it be the right thing for lightning pix , but could be just the job for wildlife photting or similar . I'm sure it triggers the shutter ,which given the camera settings would fire a flash , I don't think the intention is that you leave the shutter open , as that would only result in overexposure eventually ,anyway . I don't know about the dodging of fcc regs , but you could strike a blow to the nanny state by getting one !
It is , after all a totally passive unit that would'nt be a source of troublesome RF emission , I reckon . I have absolutely no connection with them , but I must say the gadget worked great on my Oz trip , pity most of the lightning was of the "sheet" variety in cloud . The PM picked it up every time . I ordered it at about 3 P.M. on a Monday afternoon , shipped to U.K. via FedEx , by 17.30 it was at the airport , by 05.37 Tuesday was at East Mids airport waiting customs clearance ,and by midday Weds ,was sitting in my sweaty palm , all for about $15 extra for the shipping . Most impressive . As was the extremely prompt response to the questions I posed regarding the unit . Great service - you won't be disappointed with the product or the service .