How do you celebrate the closing of a $2.4 billion deal to acquire a photography giant? We can’t say for sure, but at this time of year, we bet it involves sparklers, watermelon, and lots of stock images of American flags. Getty Images announced this afternoon the completion of its acquisition by private equity firm Hellman & Friedman, a deal that was announced back in February and received shareholder approval last month. Hellman & Friedman’s other recent media-related investments include DoubleClick, Digitas, and The Nielsen Company.