Digital BW, The Print

Okay, 

I think we are in much agreement here. I think we both agree that if a
measuring scheme of sufficient complexity is used one can plug those numbers
into your dynamic range formula and get a result. My only quibble is that
the complexity, or points of sampling, would be so extensive that the data
collected might be better used in something like a histogram, which shows a
scale of range, with standard deviation etc, rather than the relatively
simplistic dynamic range formula.

So I agree you could perform a DyR calculation on a print, but it wouldn't
be worth while for the complexity of measuring, and for the limited
conveyance of what those many measurements represent. But we are entitled to
our own feelings about this. You obviously have a close relationship with
DyR and it holds a lot of meaning for you.


>> But in the case of a print of unknown origin, the only way to count the
>> tones present would be to do a full "pixel count" along the lines of a
>> Photoshop histogram calculation. I can see no way that a few well chosen
>> samples will get you there.
> 
> I agree...that's a matter of measurement though...but I have certainly, and
> I believe most anyone has, been able to say that this print has more/less of
> a dynamic range than that print.  Whether that was intentional in the image
> or not, isn't relevant, the point is, you can visually see with your own
> eyes that two prints have different dynamic ranges.

Wow, that is so variable I wouldn't be willing to go out on a limb like
that! Since your concept of DyR is based upon the density range of the
print, and the number of tones between, if one has a greater range, but the
other has more intermediary tones, which has a higher DyR? Not an easy
choice.

I could conceive of dozens of scenarios where one couldn't eyeball the
difference in DyR as you've defined it, however, density range is a much
simpler call to eyeball.
 
>> Furthermore, tones will either be present or they will not, but
>> how many are
>> present almost certainly be based upon far more powerful determinants than
>> "noise". For instance, the number of tones present in the original file or
>> negative - or the printmakers intent!
> 
> Right, but again, you are measuring THE print, and only THE print, you don't
> care about the origin of the "missing tones".

Exactly my point. That you have no idea how many tones a print SHOULD have
is what diminishes the importance of "noise" as the defining difference
between DyR and DnR in a print. How do you characterize Artistic intent"?
 
>> But I think it's been shorthanded by the
>> printmakers
>> to dmax - dmin,
> 
> Well, that I don't agree with.  That is clearly density range, and dynamic
> range will give you a different "dynamic" than density range will.  I don't
> believe it's "shorthand" at all.  I believe density range IS density range,
> and dynamic range IS dynamic range.

And I agree with you in a technical sense. We can have two different
definition, and use them accordingly. But as you vacillate between what
needs to be measured vs what can be eyeballed, so do others, and I am
suggesting that most print makers have decided the noise component of a
print is less than relevant.

I'm not saying they are using the term dynamic range "properly", I'm just
trying to discover why your more thorough concept of DyR hasn't carried over
to printing. I believe it's because the technology has not existed until
recently to do the full "pixel count" that is required in order to overcome
the non-linearity issue. Thus your formula for DyR when applied to a print
(not a system) would as often as not yield inaccurate or misleading results!

For some reason you have not been willing to consider that different fields
may have different jargons. I don't think we can limit the scope of
discussion to your 25 years in the field, when the fields of both
photography and electrical engineering are closer to 150 years old. In
earlier years, though your concept of DyR may have held some validity, I'm
guessing a practical process to implement it did not exist, thus the
terminology was allowed to drift into a less rigid interpretation.

Or, perhaps, more than likely, it was the other way around. Perhaps the
concept of DyR had it's origins in density range, and only when measuring
instruments evolved to the point where values as small as noise could be
assessed, they invented an equation to incorporate those values. Perhaps
even then the concept of noise at the print level was not deemed a large
enough factor to bother with by anyone less than an engineer.

At this point, if you care, I really think it is incumbent upon you to
demonstrate that anyone else applies your definition of DyR to a print,
because any web search using the terms "print (dynamic range)" will inundate
you with results that suggest otherwise. At a certain point you just have to
accept that one field uses the term differently than the other, pedestrian
or not.

Regardless, in the case of a print of unknown origin, the ability to
accurately measure the entirety of a print, which is required in the face of
non-linearity, which I believe must always be considered (because it
includes artistic intent) is very young indeed. Thus, until recently it
would have been virtually impossible to apply the DyR equation and expect
accurate results.

> 
>> And if they can't perceive it
>> they don't
>> mind?
> 
> Right, but as I've said, because your eyes don't perceive it, doesn't mean
> it isn't there.

Understood, I'm just speaking from a human/artistic perspective.

Thanks,
 
Todd