Former IMAX Camera Technician - Space Shuttle In Cabin Camera .
Former Mechanical Engineering Design Technologist, Former Toolmaker, Former Aerospace CAD Design Engineer.
Stereo Photography Enthusiast since 1985 or so.
Very little. They are connected through their USB ports with spliced remote shutter cables. Both cameras fire from one camera's shutter release. You can see details on my website www.stereocamera.ca