Is it better to take the formal photographs before or after the ceremony? Before, before and before. This of course is my personal view and yours may differ, but I will explain why I feel this way. I know that some couples still like to uphold the tradition of not seeing one another before the ceremony. Largely that is to see the expression on the groom's face when he beholds his beautiful bride in her dress for the first time. That can be orchestrated and photographed much earlier, while still keeping the integrity of the surprise and capturing the REAL expressions and emotions.
With the first looks photographed the formals can commence. Think of this...is your makeup better after it has been on for a few hours or when it’s fresh? Is your hair going to look better the longer you wait? Also, if it is warm/hot, do you want to photograph sweat on your bridesmaid’s dresses? With the formal portraits done before the ceremony you can relax and enjoy your wedding. No more missing the lions share of your cocktail hour. No more being whisked out of the area because there was another photograph to take.
Another often overlooked benefit is that you can have your ceremony at sunset and still have good portraits without flash and dark backgrounds. That is why I always consult the sun and moon data website from the U.S. Naval Observatory. It tells me everything about the sun on any day, anywhere in the world (it’s free too).
I always defer to the couple whether or not they see each other before hand. It is just my recommendation that they do based on my experiences. After hearing what I have to say, it is their wedding and their call. I will deliver beautiful photographs either way. I am just happy to be part of such a wonderful day.