Originally posted by Fcsnt54 So if im reading this right, would adding more pixels on the sensor give you a better image then using pixelshift? Dont have to worry about movement, also lets say if we take each pixel and either dividing each pixel in half or quarters would give you roughly the same as shifting the sensor because the camera is having smaller sections to sample for the different colors(essentially a 72 mp without pixelshift version of the k-1 vs a k-1 with pixelshift) ? In this case im ignoring the increase of noise in less then ideal lighting due to pixel size.
In one-shot mode, a Bayer-filter camera measures only 25% of its pixels in red, 50% in green, and 25% in blue. (Digital zoom then interpolates these sparse measurements to fill in all the missing data.)
So the K-1 (and every other 36 MPix Bayer filter camera on the market*) really is only a 9 MPix red-sensitive camera, 18 MPix green-sensitive camera, and 9 MPix blue-sensitive camera.
In 4-shot pixel shift mode, the K-1 becomes a 36 MPix red-sensitive camera, 36 MPix green-sensitive camera, and 36 MPix blue-sensitive camera. In addition, the green channel gets measured twice so noise in the green channel drops.
A 72 MPix Bayer-filter camera would replicate the green-channel resolution of a K-1 in pixel shift but have poorer resolution in red and blue.
A 144 MPix Bayer-filter camera would replicate the red-channel and blue-channel resolution of a K-1 in pixel shift but have higher resolution in green.
Overall, one would need about a 108 MPix sensor to get the same average resolution as the K-1 in pixelshift mode.
(*Note: Fuji's XTrans and Sigma's Foveon are different kettles of fish with other resolution and color accuracy issues.)