Apparently not every digital camera manufacturer quit the small-sensor megapixel race, there are now 4 announced or shipping 10 megapixel cameras, besting Fuji’s 9 megapixels S9000 and E900 offerings. In itself, this increase is not much to talk about since it represents an 11% increase in total pixels. Linearly, this is a very small change. Practically, a low-noise 10 megapixel image can comfortably produce a 13″ x 19″ print, while an 8 megapixel image comfortably produces 12″ x 16″ prints. So, the difference in potential is quite small. Stretching an 8 megapixel image to 13″ x 19″ still makes a decent print, it just will not stand scrutiny with an eye right up against it. Then again, such large prints are not meant to be looked at from so close. As a matter, many photo labs print large images at a lower resolution than more common print sizes.
For those wanting to keep track, the Casio Exilim EX-Z1000 and the HP Photosmart R967 were the first small-sensor 10 megapixel cameras to be announced. These ultra-compact point-and-shoot cameras were quickly followed by an annoucment from Panasonic for two 10 megapixel camera of its own. First, there was the Panasonic Lumix FZ50 which is prosumer ultra-zoom model with full-manual controls and a standard 4:3 aspect ratio sensor (3648 x 2736). Second, there was the Panasonic Lumix LX2, a compact camera with manual controlsand a 16:9 wide-aspect sensor (4224 x 2376). Note that in 4:3 mode, the LX2 produces images of less than 8 megapixels, so its only 10 megapixel if you actually shoot in wide-screen mode!
As for large sensor cameras, the ones with sensors measured in as a crop-factor, 10 megapixel and more has been common for quite some time. The difference is that these large sensor cameras, such as the 12 megapixels Canon EOS 5D, produce images with quite low noise and so the high resolution is not seen as a problem. In itself, having more megapixels is not a problem, since it increases the potential for large prints and cropping. It is only seen as a problem when new digital cameras with improved technology end up producing lower quality images than their predecessors due to higher image noise.
What really matters is neither absolute noise nor resolution, it is noise-density. In other words, the size and intensity of noise when printed at a specific size. That is why common 6 megapixel DSLR cameras frequently produce better large prints than small-sensor 8 megapixel cameras. If you double the resolution and the noise does not double, you actually have an improvement. Conversely, if you double the noise and increase resolution by 50%, the result is a drop in image quality.
Finally, there are practical reasons to get a high-resolution camera. For one thing, companies regularly discontinue lower resolution cameras in favor of newer models. Another point is that newer models frequently include improvements over their lower-resolution ancestors. In particular, focusing speed, shutter-lag and battery-life have all greatly improved lately.