Originally posted by Anvh A shift of 0,5 pixels will mean that roughyl the same information is used to creat the same pixel,
Yes, isn't that the whole idea? Say that there is a very small detail (black dot on white backround) that on your first shot happens to fall right between two pixels, creating two gray pixels. Shift 0,5 pixels and shoot again, this time the result is one white and one black pixel (slightly simplified). Add this together and we get white, grey, black, grey instead of the original two grey pixels.
Then, as you say, we have color filters and demosaic algorithms, maybe that changes things, but my gut feeling is that is doesn't.
Anyhow, wasn't Ricoh one of the first cameras introducing this trick some 12 years ago? With the Ricoh RDC-7.