Digital BW, The Print

Austin,

I really don't want to argue these little snipets of what DyR should be
or shouldn't be.  I think its going to be necessary for you to lay the
whole thing out so we can all see the sum total of your ideas.  There's
a lot of confusion with me and I suspect others understanding some of
your points.  When stating my stuff, I tried to put in a bunch of examples
to illustrate what I was saying.  I hope you feel inclined to do the same.
I think its particularly useful if the examples are related to how we
humans perceive light and/or sound.  DynRanges of digital volt meters
or whatnot may be useful to you but don't help the rest of us "get it".

--- In DigitalBlackandWhiteThePrint@y..., "Austin Franklin" <darkroom@i...> wrote:
> Roy,
> 
> > Simplicity in concepts is so important that it must be emphasized over
> > and over.
> 
> Absolutely, but too simple, and the concept can be lost.
> 
> > Similarly the human perception of both is also completely
> > continuous.
> 
> This is the concept you seem to not be understanding.  You can have two
> sounds/tones that ARE completely different (as determinable by SOME sensing
> device), but YOU perceive them (or some sensory device) exactly the same,
> indistinguishable from each other...no matter how hard you try.  
Sorry to sound snide, but "So What?".

That IS the
> concept of dynamic range plain and simple.  
If this is DyR and its unperceivable, then "So What?".

It is NOT the OVERALL range, but
> describes what the PERCEPTIBILITY is within that overall range.  Simple as
> that.  It's relative within the range (in the analog case), NOT absolute.
> In the digital case, it is absolute.
> 
> VERY simple example.  You have one sensory system that can perceive a 1/10th
> range difference.  Another that, using the EXACT same range, can perceive a
> 1/100th range difference.  The one that perceives a 1/100th range difference
> has a higher dynamic range.

Sounds more like higher sensitivity.

> 
> EVERY sensing device has it's own dynamic range in and of it self.  Film is
> a sensing "device".  When you are using a sensing device to sense
> "information" from another sensing device, like film and a film scanner.
> The dynamic range of the scanner is entirely separate from the dynamic range
> of the film.  That also leads to why density range has nothing to do with
> dynamic range...as both can "sense" the same density range, let's say, but
> their dynamic ranges are entirely different.
> 
> Austin

So, let me paraphrase what I think you are saying with an example.  I like
to use the audio world because MAYBE we are more likely to agree.

Say I'm a audio power amp manufacturer.  I make amps, test them however
you'd like.  I put a spec in the manual stating "Dynamic Range 64db".
Is that a reasonable thing to do?   Is 64dB a property of the amp?

Now one of my suppliers comes along and says he's really improved the
test equipment.  It can perceive a range difference 10 times more accurately.
Now we can perceive i.e. measure differences in the amplifier much
more accurately.

You say and I quote from above: Dynamic Range " is NOT the OVERALL range, but
> describes what the PERCEPTIBILITY is within that overall range."
So I ask you:  Did the amplifiers just get better?  Is the dynamic range
of the amplifier now 74db  =  (64db + 10*log10(10)).  Do I have to 
reprint all the specs?

Please explain.

Roy