Wedding Photographer Clothing

Help.  I need a little help.  For years now I have been in search of a really pretty black dress to be able to wear to weddings, as the photographer.  Maybe, I shouldn't even wear a dress-maybe I should wear leggings & a really long tunic.  IDK.  I need help deciding.  Here are a few ideas I had.  Please share your thoughts!

or maybe

or maybe just black pants, black shirt & black shoes?