Pentax introduces its first medium-format digital SLR camera, the Pentax 645D. The camera sports a large 40 Megapixel CCD image sensor that measures 44mmx33mm, which is about 1.7 times larger than 35mm sensors. The 645D is equipped with the PRIME (PENTAX Real Image Engine) II image engine with high-speed data-processing capacity and new algorithm exclusively programmed for medium-format DSLR.