There used to be a higher profile local wedding photographer (maybe there still is....I don't know and don't really care), who used to wear this awful White Suit. While its good to stand out as the photographer, that was way over the top. My Wife and I looked into using him for our wedding, but found him rude and a little bit over the top for our liking.
The moral? I would say definitely dress pants and dress shirt, with a tie in the glove box of the car.....but don't try and outdo the wedding party.