Kodak DCS Pro SLR/n User Manual page 174

Flash Photography
Slow Sync
Normally the camera's shutter speed is automatically set to 1/60 to 1/125
second for flash photography in Programmed Auto or Aperture-Priority
Auto Exposure mode. However, for shooting nighttime scenes, Slow Sync
uses a slower shutter speed (down to 30 seconds) to bring out background
details using all available light.
Rear-Curtain Sync
The Speedlight fires at the end of the exposure, creating a stream of light
that follows the flash-illuminated moving subject. When Rear-Curtain Sync is
set in Programmed Auto or Aperture-Priority Auto Exposure mode, Slow
Sync is automatically set.
10-10 April 29, 2004