This is a blog post to tell you what someone told me...apparently they were told by someone else. It is a variant on the game of Chinese Whispers, except that this is called Parent Company In Japan Whispers.
Apparently Ricoh have released teaser images and specifications for their forthcoming introduction of a full-frame DSLR camera. The blat has come through very reliable commercial channels and is appealing sensible - see what i mean.
The business of having APS-C sensors or other small-frame sensors in cameras has always lead to a game of mental mathematics and advertising skittles when it came to describing what you wanted and what you got. You applied multiplication factors and then tried to figure out what you were seeing and whether it was going to be in focus or not. The lucky ones were the people who had never had a camera and did not have any preconceptions. The rest of us thought with our fingers and added up.
The advent of the full-frame sensor might have straightened out a number of minds but it left the sticky problem of small-frame lenses sometimes being applied to full-frame bodies.
Nikon said OK, and it worked to a certain extent when a Nikon body recognised what was happening ( sometimes before the shooter did ) and just used the center bits of the sensor to record the pictures. But it could sometimes confuse the user.
Canon said NO. Their small-frame lenses are physically prohibited from going onto the full-frame bodies. Buy the full-frame lens or do your pictures with a pencil and a yellow pad.
Ricoh...and for that you read Pentax...have said OK in a great way. They have decided that their new full-frame camera will accept the K-mount lenses that they have always had. Obviously they will also introduce some full-frame lenses going forward and they will probably be crackers, but for now you can clap on older K mounts from 35mm days and the ones that have served up until now with the APS-C cameras.
The plan is to have the camera automatically sense what you are doing and let you shoot the small-frame lens but only record the bit that is APS-C size. The rumour article argues that this means the whole sensor will have pretty good resolution to allow the cropped-down usage to still produce good results. it sounds like a very sensible approach to the matter - particularly if "automatic " really is so.
Rest assured, when we get to see more of the device we will show you. If you'd like to peep yourself, the web address is:https://fstoppers.com/gear/pentax-updates-teaser-its-upcoming-full-frame-dslr-107050