From Hello Raspberry Pi:
This post show how to control DSLR (Nikon D7000) with Raspberry Pi 2 (running Raspbian Jessie), using Python 2, with libgphoto2 and piggyphoto. The camera connect to Raspberry Pi via USB.
Each Friday is PiDay here at Adafruit! Be sure to check out our posts, tutorials and new Raspberry Pi related products. Adafruit has the largest and best selection of Raspberry Pi accessories and all the code & tutorials to get you up and running in no time!