Its great to have a back-up photographer ( a friend or relative) capturing those spontaneous moments on your wedding day ...but if you want something more than family snaps to look back on, a professional photographer is the safest option. Remember, you get no second chances with wedding photographs!
The professional quality of your wedding photographs is as much about good planning, build a rapport between the photographer and the couple an being able to coordinate people without intruding on your day - as it is about good equipment and photographic technique.