On Mon, 09 Feb 2009 01:32:10 -0500, John A. wrote:

and moving half a pixel gives you..?


moving 2 might give something useful

Moving a half pixel horizontally, then vertically, then back
horizontally for a total of four exposures would give full coverage
for each color in a Bayer pattern. (Double coverage for green,
actually.)

Moving 1/2 pixel isn't enough. Starting from a point centrally
located between 4 pixels, one way for a movable filter array to have
each filter color reach of the 4 pixels would be :

0. Move down 1/2 pixel and right 1/2 pixel

1. Click! Move up 1 full pixel

2. Click! Move left 1 full pixel

3. Click! Move down 1 full pixel

4. Click! Move right 1 full pixel

5. Go to #1 for each successive photo

The same four positions could also be reached by either shifting
or rotating the filter array along a circular path, where the
diameter of the circle would be equal to the distance between 2
non-adjacent pixels, presumably the distance between an Red/Blue
pair or a Green/Green pair.