> 3 minute read

Master Rear Curtain Sync Flash

Rear curtain sync flash is a creative way to photograph moving subjects, and one that can give a really good impression of speed.

The TTL flash tech that’s built into many X Series cameras makes balancing flash with ambient light as easy as pie: select the exposure mode you want to use, set your flash to TTL mode, and create! When light levels get low, you can also select TTL Slow as the TTL mode, which forces the camera to use long shutter speeds in order to let in more background ambient light for a natural-looking result. But when we use long shutter speeds with flash, we also need to decide when the flash fires.

We can make the flash fire at the beginning of the exposure (front curtain sync) or at the end (rear curtain sync). By default, front curtain sync is selected, since firing the flash at the start of the exposure makes it a lot easier to time your shot properly and capture the moment. But when photographing moving subjects using flash and a long ambient exposure, front curtain sync pictures look strange.

The initial flash produces a static, frozen image of the subject, which then goes on to leave trails of ambient light across the frame as it moves. The problem is, the trails are in front of the flash image, which makes it look like the subject was traveling backwards. The solution is to get the flash to activate after the subject has made trails across the frame – in other words, by using rear curtain sync to activate the flash at the end of the exposure.

You can swap between front and rear curtain sync using options in the Flash Setting menu.

• Press MENU OK and scroll down to the FLASH SETTING menu.
• Select FLASH FUNCTION SETTING and highlight the SYNC. option.
• Scroll through the options with the rear control wheel, choosing from FRONT or REAR.

Although rear curtain sync flash is great for achieving special effects with moving subjects, there are a couple of reasons not to use it as your default flash mode. The first we’ve already mentioned: timing a rear curtain flash for a specific moment is really difficult.

Second, although the main flash happens at the end of the exposure when photographing with rear curtain sync, there is still a pre-flash that happens the moment before the shutter opens. This pre-flash is used to calculate the flash exposure, and happens with front curtain sync, too, although you probably won’t notice it. But when using rear curtain sync to make people pictures, the pre-flash can cause them to blink, or think the shot has been taken, both of which will spoil the end result.

So, our advice is to experiment with rear curtain sync flash, but only use it for creating intentional effects with moving subjects and long exposures.

Your Next Steps

• CHALLENGE Find a moving subject and photograph it in low light, using a long shutter speed and rear curtain sync flash. Post your best pictures to social media with the hashtag #learnwithfujifilm and #flash. You can also submit your work here for a chance to be featured on our social media channels