Flash sync speed
From The Glossary of Digital Photography
The highest shutter speed that can be used with an electronic flash. This number varies with the model of camera and type of shutter mechanism. Typically speeds are 1/60th, 1/90th, and 1/125th of a second with modern digital SLR cameras. These cameras use a focal plane shutter, and the speeds are lower than those available with a leaf shutter, found mainly on medium-format film cameras. A few digital cameras will allow faster flash sync speeds.
