purpose of slow sync is to reduce shutter speed so that sensor can capture more ambient light. this can be achieved with using fully manual or aperture priority settings, which what i use the most. it also depends on how fast is your subject moving, slow it is alright, else, use the rear-curtain sync function. a flash is a whole new chapter in photography. its hard to explain and to imagine without having hands on with a flash unit with you.

using fill flash setting doesnt necessary slows down the shutter speed. its purpose is what its name states, to give fill flash, irregardless of the background ambient.

8tvt : theory alone not enuff.. buy buy 

even with large aperture lens~ when come to portrait shots~ you still need bounce flash~
nothing beat a flashgun~ 

8tvt : As long as the flashes are set to the same channel and as long as they can receive the signal from your pop-up flash, there's no limit on how many flashes you can trigger with your body.

lwliam: how come urs is 'Gearvity'? i though 'Geavity'? lol.