Oct 27 2007
Image Sensors – Part 1
Today’s digital cameras use one of 2 types of image sensors.
CCD – Charge Coupled Devices
CMOS – Complementory Metal Oxide Semiconductor
It can be a bit confusing as CCD is a chip design, whereas CMOS is a reference to the manufacturing process. Both do the same thing; convert light into an electrical charge.
In both cases, the sensors have very small light sensitive receptors (photosites) in a grid pattern.
A CCD sensor reads the information out row by row.
A CMOS one reads it out by individual photosite.
A CCD usually requires more power than a CMOS.
A CCD is usually slower than a CMOS.
A CCD is usually more sensitive to light than a CMOS.
A CCD usually has less “noise” than a CMOS. Digital noise is analogous to the grain in film. A grainy (noisy) photo is not as sharp looking.