CCD= Charge Coupled Device. Really a tiny capacitor charged prior to exposure. When light falls on the associated diode the capacitor discharges in proportion to the amount of light that falls during exposure. The capacitor is part of a FET "Field effect transistor" so when that pixel is read the current it passes (controlled by the charge remaining on the capacitor) is proportional to the light that fell on that pixel. The current the FET passes goes through a resistor and produces an EMF of a certain voltage this is then fed to a digitiser to give the digital value of the light that fell on that pixel. It is only this lst stage that is digitised. This value is the put in the correct place in the file to make the RAW file of the image. If compression such as jpeg is wanted then further processing has to be applied. I've never heard of "charged ccd" unless it means that the capacitor is charged prior to exposure. Chris. Chris. http://www.chrisspages.co.uk -----Original Message----- From: owner-photoforum@listserver.isc.rit.edu [mailto:owner-photoforum@listserver.isc.rit.edu]On Behalf Of Gregory david Stempel FIREFRAMEi m a g i n g Sent: 15 November 2003 20:36 To: List for Photo/Imaging Educators - Professionals - Students Subject: Charged CCDs Can anyone help me understand the pros and cons to the charged CCD used in Nikon's D1x? I am finally considering a dslr and have settled on the D1x or D2H from Nikon. Any feedback would be appreciated. Gregory david Stempel FIREFRAMEi m a g i n g www.americanphotojournalist.com "The brave ones were shooting the enemy, the crazy ones got it on digital"
