Should I always set my flash setting to 2nd curtain sync everytime I use my flash?

[Jun Madayag]

Hi guys whould I always use my flash sync setting to 2nd curtain sync everytime i use my flash off cam and on cam?

When do I need to use the 2nd curtain sync mode?

[Curtis N]

Here's a recent thread on the subject:
http://photography-on-the.net/forum/showthread.php?t=639180

Here is Canon's explanation with sample photos:
http://web.canon.jp/imaging/flashwork/functions/curtain/index.html