You’ve probably noticed there are two flash synchronization modes in the G12: first curtain and second curtain.
When your camera fires, two curtains (yes, similar in theory to curtains you’d find in front of a window) open and close to make up the shutter. The first curtain moves out of the way, exposing the camera sensor to the light. At the end of the exposure, the second curtain moves in front of the sensor, ending that picture cycle. In flash photography, timing is extremely important because the flash fires in milliseconds, and the shutter is usually opening in tenths or hundredths of a second. To make sure these two functions happen in order, the camera usually fires the flash just as the first curtain moves out of the way (see the sidebar earlier in the chapter about flash sync).
In 2nd Curtain Sync mode, the flash will not fire until just before the second shutter curtain ends the exposure. So, why have this mode at all? Well, there might be times when you want to have a longer exposure to balance out the light from the background to go with the subject needing the flash. Imagine taking a photograph of a friend standing in Times Square at night with all the traffic moving about and the bright lights of the streets overhead. If the flash fires at the beginning of the exposure, and then the objects around the subject move, those objects will often blur the subject a bit. If the camera is set to 2nd Curtain Sync, though, all of the movement is recorded by the existing light first, and then the subject is “frozen” by the flash at the end by the exposure.
There is no right or wrong to it. It’s just a decision on what type of effect it is that you would like to create. Many times, 2nd Curtain Sync is used for artistic purposes or to record movement in the scene without it overlapping the flash-exposed subject. To make sure that the main subject is always getting the final pop of the flash, I leave my camera set to 2nd Camera Sync.
Shooting 2nd Curtain Sync can also be a great creative tool when shooting moving objects. Because the flash fires at the end of the exposure, the result is your subject lit and in focus, but with a trailing blur of motion.
Setting your flash sync mode
- Press the Menu button, select Flash Control, and press the Function/Set button.
- Scroll down to select the Shutter Sync option, and then select either the 1stcurtain or 2nd-curtain option for the type of flash sync that you desire.
- Press the Menu button twice to return to the shooting mode.