The new sensors use a technology called backside illumination, and chipmakers including Sony and Samsung are leading the charge to build them into a variety of cameras. And though it's a premium feature today, it's spreading rapidly across the market.
Image sensors are special-purpose, light-sensitive chips packed with complicated technology. But backside illumination, or BSI, is pretty easy to understand: flip the sensor around so the light it's detecting isn't partially blocked by a bunch of electronics. What used to be the back of the sensor is now facing outward toward the light.
The advantage, illustrated among other places in the iPhone 4 camera, is better light sensitivity. That opens up new options for camera makers. One option is to offer more pixels without degrading how well each pixel works, yielding more detailed photographs. Another option is better image quality with the same number of pixels, something that's useful when taking photos or videos in dim indoor light.
For more on this story, read Camera market flipping to new sensor technology on CNET News.