1st & 2nd Curtain Flash

Not so much a tutorial but more of a demonstration.

Normally, when a n electronic flash fires, it fires at the start of the exposure. Think of a 3 second exposure... click the shutter button, the shutter opens the flash fires and... and... and 3 seconds later the shutter closes.

Here's golf ball rolling down a slope at 1/4th of a second with flash:

ISO 800 f7.1 1/4

You can clearly see that after the flash had fired, the shutter was still open exposing the scene.

In Canon's language, this is known as 1st Curtain Sync. There is also 2nd Curtain Sync, where the flash fires at the end of the exposure:

ISO 800 f7.1 1/4

In the first image, it looks like the ball is rolling up hill ! The second image is much more pleasing.

Just for fun, the Yongnuo 568EX flash also has a "Multi" setting (a stroboscopic effect):

ISO 800 f7.1 1/4

The flash settings were 4 shots at 12Hz:


Have fun