Digital BW, The Print

Hi Todd,

> But Mike quoted you Ansel's definition of dynamic range from "The Print" ,
> which was:
>
> There are three important scales within the total range of exposures that
> can be printed. The full range from black to white is represented
> by Zones 0
> to X. Within this range lies the dynamic range, representing the first
> useful values above Zone 0 and below Zone X, or Zones I to IX.
> The range of
> zones which convey definite qualities of texture and the recognition of
> substance is the textural range from Zones II to VII. (1)
>
> (1) Ansel Adams, The Negative, Little Brown, Nineteenth Printing, 1998.
>
> Looks like he does NOT support your case.

But in fact it DOES.  He clearly states "the first USEFUL value", which is
exactly the same as "discernable signal".  Also, he is clearly outlining the
DENSITY range as being from 0 to X, and WITHIN THIS range, lies the dynamic
range.  Well, that's entirely true, and completely agrees with what I've
said.  Also, "definite qualities of TEXTURE and the recognition of substance
is the textural range..." means he's simply defining a very coarse DYNAMIC
RANGE!

> Well, I'm not really interested in the chat of the lists so much as
> published documents found through web search engines.

I find there is a LOT of misinformation on the web, unfortunately,
especially on this issue.  No surprise.

> BTW, lets just clarify, the
> discussion is whether your interpretation of the dynamic range formula,
> which you've taken from electrical engineering, is appropriately
> applied to
> a photographic print, which is more physical and chemical in nature.

Hum.  I was only using the definition/example (which is CLEARLY labeled as
an example) from Higgins, not trying to take "a formula from electrical
engineering"...  I look at it as a system property, not an electrical
property, and there are many systems that are not electrical.  Even in
mechanical engineering we used to discuss dynamic range as a viable
property.

> here are a couple that appear non-pedestrian to me.

Yea, like I said, a lot of misinformation seems to proliferate.  Just like
the misuse of resolution with respect to monitor screens...  Sigh.

> Dynamic range is simply the difference between the minimum and
> maximum tonal
> values that the film can register.

Yeah, but it isn't.  What's dynamic about it?  Dynamic means "variation in
force or intensity".  The two static numbers, dMax and dMin, used to define
density range are insufficient to be dynamic.  The changes in tones within
this density range IS dynamic, hence, why it is called dynamic range ;-)

> Yes, but whatever your notion of monitor resolution I'm sure you'd have a
> far easier time finding a source to support your interpretation.

Yeah, that's true, since the definition of resolution is a LOT easier than
the equation/concept of dynamic range ;-)

> The thing is, much of what you are saying suggests thsi all broke down in
> recent years, due to the dilution of the brain pool by pedestrians via the
> internet.

Not at all...I believe it's been a misuse of the term for a long time, but
it's certainly far more prolific because of the Internet.

Regards,

Austin