Well that new camera will be bigger than K-5 is, that I do believe. Partly why (next to the convenience of having some crop and thus not so large lenses needed) APS_H is appealing to me. It will drain battery's faster then K-5 does, so maybe instead of current D-Li90 a new battery, but just carrie a spare and you get along. AF is an important issue, since it does need a new approach to make AF-C workable. Maybe I'm sattisfied with single PRIME III that is just twice the speed that PRIME II delivers (that should be possible with new technoligy, since PRIME II design is from 2008/9).
So here's my crazy idea: MAKE TWO NEW CAMERA'S
So you design that new camerabody, with the big OVF, that new AF-module (also for al the other platforms APS-C and 645D), that new electronic design (faster processing and also for APS-C and 645D) and the new shutter (stil quiet please).
My preference is APS-H, but the idea is still the same for a Full Frame format sensor.
The base for this is an APS-H sensor of about 28-21mm with a surface of 588^2 mm and pixelsize of 7 microns or 4,75 microns.
- New Hi-iso performance (sports/action orientated) camera with big pixels and a resolution of between 12-16 megapixel.
- New Hi-resolution performance (for those big prints) camera with pixels the size of current K-5 and a resolution of 26 megapixel.
Produce this camera in batches or like in car-industrie just as they come along in the productionfase. The only real difference between them fysical would be the sensormodule (and an extension on the name) that needs to be designed based on the same electronic lay-out and fysical size and connections.
They would run on different Firmware that makes one acting as a fast camera and the other slower (but that is also implied by the data read-out from the sensor, that is ofcourse slower with the sensor that carries more pixels.
The sports/action camera with up to 8 fps and the portrait camera maybe only up to 4 or 5 fps. This keeps the amount of datatstream to handle in the camera within reach of the possiblity's of a PRIME III processor.
In wich form to pack this camera:
Well I do realize that a camera that will pack more then a K-5 does needs to be bigger. But I don't believe that it isn't possible to make it small!
Looking at: Pentax K-5 with grip attached.
And making the grip integrated with the camera, just a little smaller then on this picture (wich can be done, since there is no separated connection between them) and don't make room for two battery's or a set of 6 AA's, but make room for one larger and more powerfull battery (more power then D-LI90 has to power up everything) then you still end up with a small camera
When K-5 messures: 131 x 97 x 73 mm (5.16 x 3.82 x 2.87") then you can make a K-1 (futuring a Full Frame of APS-H sensor) messuring 131 x 145 x 73 mm (5.16 x 5.71 x 2,87") futuring two sets of grips for landscape and portrait use. In this way there is for both grips the same space to the mount-housing giving the same workingway. Maybe still under 1 kg?
With only one battery inside, wich coult use a bigger space to carrie more power there is still a lot of extra room in the body to future more electronics and bigger AF-sensor. A second SDHC slot. Maybe even a little bigger screen on the back.
Is it small then?
When I look at Canon's 1D:
Wich messures 156 x 157 x 80 mm (6.14 x 6.18 x 3.15") and weights 1230 g (2.71 lb / 43.39 oz) then this K-1 is still very small.
In this way there is enough space in the camera to cramp all the neede electronics in and choosing a form that gives maximum ease of use for photographers combined with a reasonable small camera.