The Pixel War Is So Over—Think ISO

In the early days of digital cameras, it was a pixel race. Just before the holiday buying season each year, each manufacturer tried to lap the competition by throwing another megapixel of resolution at their camera. First two, then three, until we got to today's cameras that, at least at the consumer level, usually have between 5 and 10 megapixels. Some manufacturers are still marketing megapixels, but in truth, for most casual purposes, 5 to 8 megapixels is fine.

What's the new "mine is better than yours" of the digital camera world? There are several. One is ease of use. Companies are trying to make their cameras easier to use, make transferring images easier, printing easier, and so on. Another is the lens quality and range. Many cameras now come with zooms that range beyond the ordinary 3 to 1; a name-brand lens like Zeiss or Schneider-Kreuznach elevate the camera's status.

But there is another area of contention: The ability to take quality photographs in low light. In the pre-digital days, the sensitivity of film was measured in units called ISO, which comes from the International Organization for Standardization, the developer of the standard. For film, ISO 200 was a run-of-the-mill speed, usable in daylight, but requiring a flash indoors. For indoor photography without flash, you'd need an ISO of 800 or perhaps 1600. Most of today's digital cameras are, in broad stroke anyway, working in the neighborhood of ISO 200. They work well outside, but require a flash indoors. However, we're starting to see much more attention to high-ISO digital cameras, such as the new Kodak EasyShare V1253 and the Samsung L700.

With a high-ISO camera, you can get beautiful sunsets after the sun is below the horizon, when it's almost dark but subtle colors are everywhere. You can shoot cityscapes at night, lit only by streetlights and neon signs. If you want to capture the excitement of Times Square, photograph a high school musical without the distraction of flash, or get candids of the kids as they toddle indoors you need a high ISO.

Since digital cameras increase ISO speed by amplifying the signal, the ISO gotcha is that the higher the ISO speed, the higher the noise. If the signal is amplified too much—if ISO speeds are high enough—the photos can get really noisy.

One of the reasons that digital SLRs are so powerful is that they have large sensors, which are best for producing images without noise. So the quality of the sensors—how large they are—is important. An ordinary camera working at ISO 800 will produce a noisy, splotchy picture that won't look very good. New sensors with improved abilities to let in more light are beginning to appear in consumer digital cameras. These new high-ISO cameras will produce the best-quality picture in low-light conditions.

A nice tutorial can be found at Photoxels where this image is used to teach about various ISO speeds. And special thanks to Jerry Magee and my husband Kaare for their ISO insights. Any other thoughts are most welcome.