all my realtime continuos motion scanners 8,s8, 9,516 and 35 has laser to detect the perforation, no problem at all also with transparent films, negative or copy.
there are several example on my vimeo page
this is a s8 scan of a 1971 film I made yesterday, no post stabilization, 25 fps scanner, this is HD (more than enough for s.8) but there are also example till 6K (always in realtime)