rear curtain/front curtain sync

Can anyone either give me or direct me to an explanation of these terms?

I keep seeing them used on the Forum & it's driving mr potty trying to understand

Thanks in advance!

Ralph

Very short explanation:

Front Curtain Sync

The flash fires at the beginning of the exposure. It’s the default mode for most of the times. Its creates an effect where the motion blur appears to leave the subject behind.

Rear Curtain Sync

The flash fires at the end of the exposure, it is used to freeze motion at the end of the exposure and creates the effect of motion blur leading up to the subject.

take capturing an image of a moving vehicle for example............

front curtain chain of events:

"Flash"(image frozen).

Due to (relatively slow) shutter speed chosen vehicle's forward motion continues to be captured by sensor.

Image result shows blur in front of vehicle.

Image result may appear as if the vehicle was moving backwards at a high rate of speed?

Rear curtain chain of events:

Shutter opens,

Sensor immediately begins recording moving vehicle resulting in blurred image.

Just before curtain closes, ending the image capture, the flash fires resulting in freezing the vehicle at the end of the forward motion of the car's movement through the composition.

Blurring exists at the rear of the moving vehicle. Front of vehicle is frozen in time. Some may say resulting in a more "believable" image capture.

hope that helps with the explanation..............

b

I realized that it seems that my answer and bobf's one are the opposite but it's the same since we didn't explained well.

My explanation works when the camera follows the subject so its stays in the same position in the frame. In Bobf answer the camera is still and the subject is moving in the frame.

Here's an example of rear curtain sync:

Rand