As I have been telling friends for quite a while now, megapixels are no longer a key metric for deciding between different digital cameras. For relatively inexpensive cameras with small lenses, there is probably no advantage to having any more than about six megapixels, in terms of the quality of images you will get. Indeed, having too many pixels crammed onto a small sensor can start to decrease image quality, as pixels that are overwhelmed by the amount of light hitting them ‘leak’ into neighbouring ones. Images from sensors with unnecessary megapixels also clog up memory cards and hard drives, and mean that you need a very powerful processor to deal with large numbers of them at a time.
Akira Watanabe, manager of Olympus’ SLR planning department, has declared that twelve megapixels is adequate for all consumer purposes. Furthermore, he has declared that Olympus will now focus their attention on other issues, such as dynamic range, colour reproduction, and low-light image quality.
From a photographer’s perspective, this is very good news. I have taken plenty of great photos with a 3.2 megapixel camera, and subsequently blown up some of them as large as 11 x 14″. At the same time, most small digital cameras have poor performance in low light and problems addressing dynamic range. At this stage, improvements in those areas are a lot more valuable than cramming more pixels onto their sensors.
Of course, it will cause a bit of trouble for people selling cameras in big, non-specialist retail outlets. When I worked for Staples, I was never given any information on products beyond what was written on the little information card in front of it. While it is easy to say: “This camera has eight megapixels, that one only has seven,” it is a lot harder to test, understand, and express more subtle photographic characteristics.