Archived posting to the Leica Users Group, 1999/10/14

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Subject: [Leica] Re: Leica Users digest V12 #68
From: Alexey Merz <>
Date: Thu, 14 Oct 1999 15:41:22 -0700

Alexey Merz:
>>Nope. The electon signal accumulated in the CCD potential
>>well has to be amplified prior to "counting" in the A/D

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