Digital Cameras: Listed By Megapixel
(Dave here:) In the earlier days of the digital camera revolution, resolution (megapixels) was a much more important specification than it is now. This was because the low resolution of early models limited the size prints you could make. You could make an acceptable 8x10 inch print from a 2-megapixel camera's files, but three megapixels would produce a sharper-looking print. Four- and five-megapixel cameras let you crop the images somewhat and still have enough resolution left to make a decent 8x10.
These days (this is being written in mid-2007), it's hard to find a digital camera with fewer than 6 megapixels, and some consumer models have sensors as large as 12 (!) megapixels, and I've no doubt we'll see even higher resolutions in the years to come. If 3-megapixel cameras could make good-looking 8x10 inch prints, is there really any advantage to 12-megapixel models?
Good question. The short answer is that there really isn't any advantage to having 12 megapixels in your consumer digicam, and the itty-bitty pixels that result actually hurt matters somewhat when it comes to image noise. Image noise and high ISO (high light sensitivity settings) are a whole other topic, more than we can go into in this short note, but suffice to say that cramming more pixels on the same size chip adds little in the way of usable resolution, and makes it harder to get clean-looking images when shooting under dim lighting.
The one thing that can be said about higher megapixel numbers on cameras is that, within a given model line, you'll tend to find more advanced capabilities and snazzy features on the higher-end models, which generally also sport the higher-resolution sensors. So higher megapixel ratings are a possible indicator of more feature-rich cameras. That said though, a better indicator of whether a camera is high- or low-end is simply the selling price. (Of course, when looking at models from different manufacturers or even from different lines by the same manufacturer, neither megapixels nor price are likely to give much idea of how the comparative features stack up.) Most readers will be best served by simply comparing models that fit within their budget, looking for the features they're interested in, and then using our reviews and sample pictures to pick out the ones that perform the best and take the best-looking photos.
Given all the above, rather than trying to explain the practical differences between different megapixel ratings as it once did, this page now simply lists megapixel ranges (see above and below) that are currently in the market, for those readers still interested in this distinction. Because they really belong in a class by themselves, we've listed digital SLRs on a separate page of their own, regardless of resolution rating. (See our article Digicam or SLR? for a good overview of the differences between the two types of cameras, and the pros and cons of each.)