Size matters! Electronic cameras capture images using a light-sensitive imaging chip. The surface of this chip is covered with tiny sites that generate an electrical charge when hit by light. The amount of this charge is hardly measurable and thus photographically useless. Both a large camera and a phone camera must apply amplification to bolster the charge in each site.

Now bigger is better because larger cameras have larger sites (pixel short for picture-element). A larger site will receive more photon hits; thus the degree of amplification required to get a useful signal is greatly reduced.

The amplification we are talking about is comparable to upping the volume of a radio. As we turn up the loudness, we are applying amplification. Sorry to report that electronic signals contain good and bad components. When we amplify we increase both, but not always uniformly. The bad in the case of the radio is called static. The bad in an electronic camera is called noise.

The bottom line: The bigger the camera, the bigger the imaging chip. Big imaging chips have bigger pixels which need less amplification. The less amplification, the better will be the picture quality.