Megapixels and the Camera World

The first thing anyone asks me when they see my Canon G9 is “How many megapixels does it have?" My answer, 12, causes a swoon. The trouble is, I neither want nor need that many. My Nikon D60, with just 10 megapixels, takes better pictures, especially in low light. In fact, when Nikon announced its new P6000 two weeks ago, I groaned when I read the sensor size: 13.5 megapixels. All those extra dots add up to one thing: noise. Here we take a look at the advantages of smaller pixel-counts, and what they mean for the future of photography.

Fast ISO

ISO ratings on digital cameras mimic the different sensitivities of film, but they don't quite work in the same way. The same information falls onto the same sensor, but at higher sensitivity settings the signal is simply amplified to make things brighter. Unfortunately, any noise is also amplified, which is why we normally see noisy images at high ISO settings, despite improving noise-reduction software in cameras.

And the more megapixels on a sensor, the more noise; those pixels are so small and so close together, especially on the tiny sensors in compact cameras, that information bleeds between them, a kind of visual cross-talk. Nikon was the first company to have the cojones to release a flagship DSLR, the D3, with “only" 12.1 megapixels. This relatively low count, coupled with a full-frame sensor, means that the D3 can shoot amazingly low-noise photos at ISO 6400, with pretty good images all the way up to ISO 25600. This has left Canon, still focusing on pixels, scrambling to catch up.

Burst Mode

Almost every compact camera comes with a video mode, and many shoot in high definition. If pixel counts were to top out at, say, 8 million, the camera's processors will soon be powerful enough to shoot video at full resolution. Why do you care? Because if a camera can grab frames that fast, shutter lag (still a problem on compacts), blinking subjects and forced smiles are all moot: You simply review the burst of images and pick the one you want. Sure, this will fill up your memory cards quicker, but that's just another reason to keep pixel counts low. Casio already does something similar with its Exilim EX-F1, which shoots 6-megapixel images at 60 fps.

GPS

This one is independent of pixel count, but - we predict - will soon be in every camera. In-cam GPS means that the picture can be stamped with location coordinates; not just when it was taken, but where, meaning that it can easily be placed on a map, automatically. It also means that you can search out other peoples pictures taken in a certain place, even finding out where the pros stand when they take their amazing photos. So far, the only big name to add GPS to a camera is, again, Nikon, with its new P6000. Anybody spotting a trend here?

RAW

RAW, like GPS, should be available on every camera. The RAW file format, although different for almost every single camera model, is the closest we get to a digital negative. It is essentially the RAW data from the camera's sensor, completely unprocessed, unlike JPEG files which are white-balanced, sharpened and compressed in camera. A RAW file might need a little extra work in post production, but you are working with all you camera has to offer, including increased exposure latitude.

RAW files are, by their nature, bigger than JPEGs, but I'd warrant (unscientifically) that an 8-megapixel RAW file will contain more information than, say, a 12-megapixel JPEG, and be of a similar size. So, the combo of RAW and a small pixel count means better images.

Aside from this list, a slowdown in the megapixel arms race would leave the technicians at Canon and Nikon to concentrate on new ways to make the cameras better for the photographer, instead of laboring to squeeze yet more dots onto their chips. Unless you are actually printing your photographs, and blowing them up to the size of posters, the camera in you pocket has all the sensor you need. Imagine, then, that same camera, only that you never miss a shot, never forget where you took it and, above all, never need to turn on the harsh, on-camera flash.