A lot of my friends buy cameras based on the number of megapixels and then expect higher quality images. Image sensor size (actually sensor density) has a much higher correlation with image quality than the number of megapixels. Larger sensors typically capture images with less noise and greater dynamic range than smaller sensors. Wikipedia has a great graphic that illustrates the size of sensor found in most common cameras (click for original graphic size). Sites like dpreview.com offer statistics on image density. Consider sensor density when buying your next camera.
Very helpful graphic. Can you give examples of cameras with the smallest sensors (bottom row)?
“Sensor” usually refers to the whole chip; you use it to mean the individual photon-counting cells, so what term do you use to refer to the whole chip?
“Consider sensor density…” needs a little more clarification:
“Consider sensor density (denser = more, smaller, less precise sensors on a given size)…”