This Field Guide provides a concise summary of the photographic imaging chain and explains the connections between the science and photographic practice. It summarizes the fundamental optics required for understanding photographic formulae. The relationship between the photometric exposure distribution at the sensor plane and the resulting digital raw data produced by the camera is described, as are the steps required to convert raw data into an output color image for a display. Other topics include focusing, framing, depth of field, photometric exposure, lighting, strategies for obtaining a suitable exposure, and camera image quality.