[leung1222]

快門???
ISO????
???????

Too many unknow???

If you pan your cam, to get the light...why the DJ face so clear?
It shoud be Blur, cos you pan the cam.

If you use second sync, the pics should be very bright, am I right?

picture 1
http://www.dcfever.com/photosharing/enlargephoto.php?photoID=376477

picture 2
http://www.dcfever.com/photosharing/enlargephoto.php?photoID=376478

[tam_dominic]

DJ is the closest subject and the only light source is the flash light.
It exposed for quite a long time eg 1 second or over 1 second with camera moving during the exposure.

Since the flash light last only for about 1000th seocnd, the DJ are sharp.
The flash is not strong enough to cover the background thus only the moving light tracks are there.

You may experiment without difficulty.
Happy shooting !

[six_seven]

多重曝光加後簾閃光燈!