Slow Sync Flash

Slow sync flash is a method of using flash during a long exposure shot specially during low light photography. Most cameras have the function to shoot both a longer shutter speed as well as firing a flash. Using this function we can get relatively sharp shot of the main subject as well as get some ambient light from the background.

There are two methods for slow sync flash photography

1. Rear Curtain Sync
2. Front Curtain Sync

Rear Curtain Sync:

Rear Curtain mode tells the camera to flash at the end of the exposure. Once you click on the shutter, the lens is opened to collect light and just before the shutter is closing there is flash fired helping to freeze the main subject.

Front Curtain Sync:

Front Curtain mode tells the camera to fire the flash at the beginning of the shutter release and then opens up to start collecting the light.

Differences between the two modes are mainly noticed while shooting motion pictures specially Panned pictures. Most of the sports photographers use Rear Curtain Sync to shoot panning pictures.

You can see one of my Rear Curtain sync flash photography in this article. Exposure of this shot is 5 seconds. The long exposure helps me collect light for longer duration and flash helps me freeze the actions of the bubble at the end of the shutter release.