[filmscanners] RE: Newish Digital Tech

["Austin Franklin" <austin@darkroom.com>]

> > Hum.  Is that true?  I don’t know that I believe that.  What,
> exactly, do
> > you mean by noise?  Noise has MANY sources.
> >
> > I believe the more accurate the number of photons you capture, the more
> > accurate your information.  Also, the more accurately you
> characterize the
> > loss, as well as the more repeatable it is, the more accurate your
> > information.  It also depends on the accuracy of your sensor.
>
> Of course there are other noise sources. But light, just light
> electricity,
> is a statistical process. At high light levels, as at high current levels,
> the number of photons or electrons is so large that the random
> fluctuations
> are a small percentage of the total. If you double the number of photons
> that you capture, the random variations only increase by the
> square root of
> two, improving the signal-to-noise by 3db.

Paul,

I’m still trying to understand what noise you are talking about.  Perhaps
“shot noise”?  The formula for shot noise is:

shot = sqrt S

Where S is the signal, and both are expressed in electrons.

Typically, CCD imaging sensors are limited by shot noise.

Austin

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