Pentax have made patents on the following camera. Probably something that will never be released :
US6337955: SLR camera which can selectively utilize light-sensitive film or an image pick-up device An SLR camera system includes a camera body, an interchangeable lens having a lens shutter, a film back and a digital back which are selectively attached to the camera body, a drive mechanism, provided in the digital back, which drives the image pick-up device in a direction of an optical axis of the interchangeable lens, and a controller. When digital back and the interchangeable lens are attached to the camera body, upon receiving a shutter release signal, the controller controls a focal plane shutter provided in the camera body to fully open and subsequently controls the drive mechanism to advance the image pick-up device to the focal plane before controlling the lens shutter to operate, controls the drive mechanism to retreat the image pick-up device, and subsequently controls the focal plane shutter to shut after controlling the lens shutter to operate. - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .

