Some Nokia devices (for one example I know of: no doubt there exist other cameras and camera phones that do something similar) have a higher resolution CCD than they need for unzoomed images and use the extra resolution for noise reduction and such when scaling the image down to the final size - so with zoom you genuinely get more detail but possibly at the expense of extra signal noise.
Some Nokia devices (for one example I know of: no doubt there exist other cameras and camera phones that do something similar) have a higher resolution CCD than they need for unzoomed images and use the extra resolution for noise reduction and such when scaling the image down to the final size - so with zoom you genuinely get more detail but possibly at the expense of extra signal noise.