Sometimes you don't want second curtain sync. By definition, second curtain (or dragging) lets some ambient light onto the film/sensor. It could be that there is considerable ambient light falling on the model but not enough to ensure a decent shutter speed to avoid camera shake so you opt to use flash. With 1st curtain(no dragging) the ambient light will have negligable effect on the model but will probably some background detail to a degree. Not a bad effect especially if you can hand hold at a slower shutter speed.
With 2nd curtain it is possible that the lens is open so long that the ambient light falling on the model will begin to register an image on the film before and in addition to the flash exposure which follows. What you then get is a strange effect where the subject is both blurred (camera shake) and sharp at the same time.
I have an Olympus Evolt and it has three shutter modes.
1. 1st curtain with a higher shutter speed (results in black background)
2. 1st curtain with a slow shutter speed (allows some of ambient light to register.
3. 2nd curtain with a longer 2 second exposure( deliberately creates the trailing light behind the subject)
Hope this helps
Paul
|