Pixels and shooting at various resolutions?

Hi,

I'm using a Fuji S7000 digital camera. When shooting at various resolutions (1
to 6 megapixels) what happens to the pixels. At 2 megapixels I have 1600x1200;
at 3 megapixels I have 2000x1500 roughly. Is it just fewer pixels used at the
lower resolution or something else?

Do all cameras work pretty much the same way in using pixels at various
resolutions?

TIA,

Conrad

Conrad Weiler
Camp Sherman, Oregon

What happens in most cases is a sort of averaging. Lets say your
camera has an array of 2000 x 1500 pixels. If you shoot at 1000 x 750,
then each new pixel is basically an average of a two by two array of
actual detector elements. Now, in many cameras the algorithms are a
bit more complicated than a simple averaging, but that is the basic
idea. They divide up the outputs from all the pixels in 2 x 2 blocks,
and take an average (plus maybe a little extra math) and the average
from that four-pixel block becomes one new pixel in the lower
resolution output. It is not necessary for the reduction to take even
numbers of pixels to average, one can average "fractional" values for
resolutions not an even divisor of the original array.