Is SB400 suitable for wedding .
depends on what u wanna do. if it works in ur situation and setup, it's suitable.
cameras are not made of tofu
dun think so.
depends alot o the ambient light at your location
also the ISO you are going to use
and your style of photography
so the answer is still yes/no
a few things that might concern you with using SB400:
- flash power
- possible tilt angles
- cycle time
- durability after repeated flashes
Are you gonna be the main photog, or just going around taking photos of friends/family?
It's very good for general use like group shots (not super wide type), but have to be careful with longer lens with hood, may cast shadows.
I like its size,weight and power, unfortunately many 3rd party diffusers can't fit it.
Professional paid shoot or casual candid group shoot?
Answer is obvious......