3.1. Digital Imaging Sensors

Camera manufacturers must consistently deliver innovation. Megapixel counts have reached a level that is more than sufficient; they already surpass the resolution we could get out of film. So that war is over. The new battleground is dynamic range (DR). And the battle has begun already. The popular camera testing website Digital Photography Review (www.dpreview.com) has picked up DR as a test criteria, using a designated test setup with a backlit grayscale chart.

Sensor technology is the motor of this innovation, and charge-coupled devices (CCDs) have been dominating this field since the eighties. A consumer-grade CCD can capture a dynamic range from 60 to 70 dB, which is equivalent to 10 to 11.5 EVs. High-end CCD sensors reach 78 dB (13 EV), but that's about the upper limit of CCD technology. By comparison, a sunny outdoor scene can contain 100 to 150 dB (16 to 25 EV).