As a sidenote this only happens with faster shutter speeds than about 1/250 sec, which also happens to explain why "high speed synchronization" of flashes is ne

As a sidenote this only happens with faster shutter speeds than about 1/250 sec, which also happens to explain why "high speed synchronization" of flashes is needed and visualized here: http://webs.lanset.com/rcochran/flash/hss.html http://webs.lanset.com/rcochran/flash/hss.html