Archived posting to the Leica Users Group, 1999/10/15
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]I read this email. had no idea what was being said. but I really liked it. then Alexey ended with "like, duh", and I felt REALLY insignificant. Rob Mueller - -----Original Message----- From: Alexey Merz [mailto:alexey@webcom.com] Sent: Thursday, October 14, 1999 6:41 PM To: leica-users@mejac.palo-alto.ca.us Subject: [Leica] Re: Leica Users digest V12 #68 Alexey Merz: >>Nope. The electon signal accumulated in the CCD potential >>well has to be amplified prior to "counting" in the A/D >>converter. Anthony Atkielski: >No matter how much you amplify it, you still get discrete levels. >Every additional electronic adds one indivisible unit charge. Bullshit. No actual MOSFET amplifier used in even a high-zoot CCD will feed a signal into the A/D converter sufficiently noise-free that the A/D converter will relibly report whether 17586 electrons or 17587 electrons had accumulated in a given potential well. Hell, the pre-amplification readout noise is greater than that. You are simply mistaken. There is *nothing* quantal about the signal that leaves the CCD. By any practical definition, pixel amplitude is an analog signal prior to its interpretation at the A/D converter. That's why it's called an A/D (analog/digital) converter. Like, duh. - -Alexey