QUOTE(vmh90 @ Dec 29 2015, 01:14 AM)
built in flash alrdy bright enough, need a stronger flash?

for what i see, you're totally dunno the importance of flashes. regardless built-in flash or external flash, they have their guide number (GN)? that's represents their flash power. furthermore,
not all flash coverage are same1st, most DSLR built-in flash GN is around 10 to 12, and mirrorless camera built-in flash GN is around 4 to 7
2nd, there's a formula of maximum distance flash can light up the subject
GN / aperture = the distance flash can reach
let say, A6000 flash GN is 6, and if u set the aperture F4,
6 / 4 = 1.5meter
means the maximum distance flash can light up the subject is 1.5 meter
so, if u use built-in flash and take photo, 3 or 4 meter to the subject, with smaller aperture, u will ended up of subject is underexposed, or totally dark. although u can raise ISO sensitivity to brighten up the exposure, still, u raise the noises
external flashes not only have stronger GN, novice level flashes can tilt for bounce the flash to ceiling, wall, reflector or something can bounce the light off, to create softer, lesser shadow, etc... furthermore, with external flash, user can adjust stronger flash power and set lower ISO sensitivity for take brighter photo with lesser noise even indoor photography. thers's soooooooooooo many things external flash can do what built-in flash cannot perform
most novice level external flashes have at least GN32 and above, and user can adjust the flash power and flash coverage as well