[filmscanners] RE: Dynamic range

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

Roy,

> I can't figure out why you and Austin have such a mental block about
> ranges and ratios.

And I can't figure out why you want to argue about this.  Every reference
I've cited (and others have cited) agrees with me completely...I still don't
know what on earth you're trying to claim...as you keep changing it.

> In all the situations we're talking about, they are
> just plain one and the same.  Dynamic Range is a ratio AND its a range --

Can you point me to ANYWHERE on earth that says something to the effect "we
have a dynamic range that goes from .01 to 3.2" or something like that?  No,
because dynamic range is ONE number, as clearly specified in EVERY dynamic
range equation.  It is NOT a RANGE of numbers.  A specification of dynamic
range, say, 92dB, does NOT give you ANY range, it merely gives you the
information about the relationship over a (unknown) range.

You are confusing that dynamic range IS calculated OVER a specified range,
but it is NOT a range in and of it self, and simply because you calculate it
FROM a specified range, does not make it a range.  That's silly.

> Similarly, Dmax - Dmin is a ratio and
> its also a range

How's that?  That's a "MINUS" sign, not a "from - to" in the dynamic range
equation.  You certainly could SAY that something "over a range from dMin to
dMax", there is nothing wrong with that, but that is NOT dynamic range,
that's simply a density range.

> -- looks like a density range (a range as well and its
> a ratio).  They are ALL the same kind of animal.

Well, no...density and dynamic range are similar, only in that they are both
represented typically in log values, but that's a so what, and doesn't make
them the same.

> Todd is reading and interpreting the ISO standard and that audio paper
> entirely correctly.  Listen to him.

Todd is confused by this probably because you, and some others, have some
real misunderstandings as to what dynamic range is, and you are simply so
prolific, and so out of focus, and want to argue the minutiae instead of
understand the overall concept, no wonder people are confused.

So much for your promise to not post any more on this...

Austin


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