Be warned and consider the consequences of any DJ offering "Zapp photos" or is a DJ that brings a photographer with them. This photographer will take instant photos which will be displayed on screens at the reception. Usually the photos are poor quality taken with cheap equipment. It is a novelty meant to entertain - but it presents a hugh gap in ethics and most importantly will usually violate the contract you have signed with your professional photographer. The DJ vendors that choose to do this as a boost to their revenue do so at the risk of legal action and certainly do not respect the couple's decision to have hired a professionals. Stay away from "entertainment' vendors who offer 'packages' or who think they can do it all. Something always suffers in that case - and it could be at the couples expense.