Shutterstock is buying BigStockPhoto, another stock photo site, as it looks to introduce new payment methods. No financial details were released. BigStockPhoto lets users purchase individual photos by buying “credits,” while Shutterstock only offers subscriptions. Both sites let photographers upload photos. Shutterstock is keeping BigStockPhoto as an independent site. As CNET points out, the acquisition follows a wave of consolidation in the industry. Getty Images (NYSE: GYI) purchased Jupitermedia’s online images unit for $96 million last October. Release.