The 645Z Medium Format DSLR Camera (Body Only) from Pentax features a 43.8 x 32.8 mm CMOS sensor with 51.4 effective megapixels. The sensor is designed without an anti-aliasing filter to maximize sharpness and details. RAW files can be recorded at 14-bit and saved using either the proprietary PEF format or Adobe's DNG format.

An ISO range from 100-204,800 and high S/N ratio provides low noise, low light capability, and the Prime III image processor lends itself to fast image capture with a maximum of 3 fps continuous shooting. The SAFOX II autofocus module utilizes 27 autofocus points including 25 cross-type sensors and 3 AF sensors dedicated for low light focusing. The new Real Time Scene Analysis System features an 86,000 pixel RGB light-metering sensor for enhanced accuracy of exposure, white balance, and auto-focusing.