Kens Photography Blog

High end flashes like Sigma EF DG-500 Super has many great options that unfortunately is never used by new photographers. One such feature is Second Curtain Flash.

Your digital SLR camera has 2 curtains that act in sync when you take a photo. When you press the shutter release the first curtain opens up and stays up for as long as the exposure time, and then the second curtain comes down, closing the lens to end the exposure.

Normally, when you use flash, the flash fires right after the first curtain opens up and that’s where the motion (if any) is “frozen”.

Now imagine that you are using a slow shutter speed, and there’s motion in the scene you are shooting. Since the flash fires at the first curtain, and the slow shutter speed captures motion trails, these trails will appear in front of the subject, and the subject will be behind the streaks, making the subject blurry.

We can fix this using second curtain flash.

Since second curtain flash fires the flash at the end of the exposure, motion trails will now be correctly behind the subject, and the subject in motion is frozen at the end of the exposure, the subject will be crisp, with cool motion trails behind.