Digital BW, The Print

on 4/5/02 11:29 AM, Austin Franklin wrote:

>> The reason I'd stay with it even longer (Ya, I hear the
>> groans) is because underlying the contentious aspect of it is a search to
>> describe much of what we are looking for in a print; working towards or
>> against in our work; and a means to communicate about it.
> 
> Which is EXACTLY why I believe dynamic range is an important
> concept/property to understand and distinguish from density range.

I agree. I think they course this thread took has caused us to get lost in
the trees at points and loose sight of the woods. But that's nobody's fault,
it's challenging topic that needs to be hacked at from different angles.

Where I stand now is this: the concept of the ability to distinguish "micro
contrasts" within a larger "macro contrast" (density range) is interesting.
(Thanks for defining it as such Roy.) I think the formula you provided is
probably very workable in a scenario where noise is easily defined and it is
reasonably linear across the useable density range, so one or to points can
get integrated together, and give a useful number. However, when you get to
the point where you need to assess noise across the density range, because
it may be nonlinear within it, then I feel a different representation of
those measures would be more useful, like with a curve plot or histogram.

So, ultimately I like the concept you've maintained, it's just what it's
named and how it's applied/described that gives me pause. You've maintained
that for other fields the term dynamic range spoke to that concept, and it
should have in photography too, but instead the term got dumbed down to
represent density range. You're probably right. That may have occurred
because in an analog and non-linear world the calculations and descriptions
of that "contrast within a contrast" notion got more complicated, noise
becomes less of a limiting factor relative to optical phenomena, thus
formulas more complex than yours were applied, leaving the term "dynamic
range" unattended so to speak.

That's my little two minute summary of what I've taken from this thread so
far. What do you think?

Todd