[filmscanners] RE: Density vs Dynamic range

["Austin Franklin" <darkroom@ix.netcom.com>]

> However my point is that if you can reduce the noise level then you can
> increase the number of steps (by halving the step size) with real
> benefit, but without altering the range.

Hi Peter,

Correct, but that INCREASES the dynamic range.

> My principle argument was that a 5000:1 ratio does not specifically define
> that 5000 steps are requires

Well, yes it does...that's what it means, with respect to what we are
talking about.  Go download a few linear CCD specs (or if you want, I can
mail you some), and you'll see they talk about it in exactly the same way I
do.

> Just a quick question - do CCDs really use a +/- voltage swing? I'd have
> thought that would have introduce noise problems around 0.

Not necessarily, but A/Ds do.

Regards,

Austin

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