You DID hire a photographer, he can do his work after all! So you would prefear to have your friends and family enjoy the evening without phones.

How do you inform guests that we don't want them to take pictures at our wedding?

You need to spread the word! Just use a few different tactics: 

- start by telling your closest friends and family;

- then add a note to your wedding website;

- last but not the least add an "unplugged wedding welcome sign".

As long as you're polite about it, your guests will respect your decision!