Digital BW, The Print

Hi Todd,

I don't mean to single you out, in fact I think this flavor of response is
felt by several people.

I got myself into the middle of this mess more from a philosophical 
point of view than a technical one.  It seemed at the beginning most of
the discussion was at the technical level so I joined at that level.
Unfortunately, the technical level of different people just varies too much
to get a feeling of consensis. 

To me it boils down to this.  Imaging has been around in many forms for a
long, long time.  I'm talking decades to a century.  Our group here is a small
niche of  the whole Imaging world history.  We may be significant to inkjet
quadtone printing but we all use significant other parts of Imaging.
The notion, the term, the usage of "dynamic range" has been a part of
imaging way beyond just our group's influence.  It's had a very consistent
meaning describing the "useful range of light values" in whatever terms that
are appropriate for a particular imaging technology.  (I guess you could
dispute my claim, but at least come up with at least one example).

So, how can we here is our niche, talk about coming up with a new idea,
new concept of what "dynamic range" means?   We a just a part of a large
community of imaging that long time ago has defined and has commonly used 
this term to mean sometime very specific.  Even contemplating having our
very own "dynamic range" concept that differs from the rest of the world
just seems totally crazy to me.  It doesn't matter how good the idea is,
I just can't imagine how it makes sense to use an existing term.  We have
to talk to other people, use other technologies, read specs, you name it.
Let's make it easy to communicate with the outside world!

Best regards,
Roy


--- In DigitalBlackandWhiteThePrint@y..., Todd Flashner <tflash@e...> wrote:
> 
> 
> > It seems wrong to leave the impression that Austin's position, although
> > apparently intractable, is without merit.
> 
> I don't think any of us believe Austin's notion is without merit, it's just
> that he hasn't demonstrated that anybody but him thinks it's worthy of
> pursuing WRT prints. I don't mean that to sound too cynical, I just mean he
> makes some sense, but it doesn't help his case that he hasn't provided
> evidence to support his notion that the DyR formula is meaningful in this
> context. "Noise" in analog photography is typically from grain, but silver
> papers don't really have a visible grain to speak of, so we don't know what
> Austin refers to when he states his formula.
> 
> However, there are things that can affect the "tonality", or tonal
> distribution, of a print - flashing was one previous example - and having a
> neat little formula for expressing those qualities might be useful, though I
> doubt it. We speak of the shape of a paper's characteristic curve, hard or
> soft tonality, creamy tones, soot and chalk tones. These are some of the
> characteristics I thing Austin is thinking of when he speaks to a prints
> dynamic range, but the question is, can you ascertain those qualities from
> [(dMax-dMin)/noise]? If I tell you one paper has a dynamic range of 2.2 and
> another 2.8 do you really envision them any other way than that one has a
> greater density range than the other?
> 
> Ultimately it's not a question of could you apply Austin's formula, it's
> would you?
> 
> I find it interesting that for all DyR's reputed relevance to photography,
> even Photoshop doesn't include a DyR analysis of a file. Why? I believe one
> reason is because it can't know what a file's input values were supposed to
> be, and thus can not determine what in the file is "noise". Instead
> Photoshop does a far more complex analysis of a file, quantifying every
> pixel, and expresses those results in terms you find in the histogram such
> as Mean, Standard Deviation, Percentile, etc, - but no DyR. My only point is
> that it would seem that DyR, while very useful in some applications, is out
> of place in others. I would guess it's out of place where noise is not a
> known, or relevant, quantity or quality.
> 
> When Austin defines "noise" WRT photo paper, demonstrates that typical photo
> papers contain noise to a significant degree, and shows that someone of
> repute - other than himself, ;-) - has applied his formula to a print and
> gotten meaningful info from it, he may well win all of us over.
> 
> I'm kinda rooting for him, as I'm sure many of us are, but he's not there
> yet... ;-)
> 
> Todd