Digital BW, The Print

on 3/31/02 11:55 AM, Austin Franklin wrote:

> There is also another issue that hasn't been brought up.  If the eye can see
> 100 tones, what EXACTLY does that mean, with regard to a print.  Here are
> two extremes.  We have a full tonal range from dMin to dMax, where dMin and
> dMax are at the limits of the printing process.  Second print, has 100
> tones, but they lie in a VERY limited range of the overall ability of the
> printing system...the dMin and dMax of the actual print are much much
> smaller than the dMin and dMax of the ability of the printing system can
> achieve.  What do we see?  I believe we CAN see 100 tones, if in the right
> light...simply because of how our eyes work.  Now, I honestly don't know the
> answer to it, but the point is, if what I am theorizing is true, the dynamic
> range becomes more significant, than if we just assume 100 tones across the
> entire printing range is sufficient...  Unnastan?

Hi Austin

This is an interesting scenario and I'm glad you brought it up.

Since you've maintained that one interpretation of DyR is the number of
tones present in a print, by definition these two prints have the same DyR,
in spite of drastically different density ranges. This speaks to my trouble
with the whole concept.

First off, it would make one assume the print with the greater density range
must have an enormous amount of noise to keep it's DyR as low as a print
with a much lower density range, while it could just be the print accurately
reflects the 100 tones of the original with negligible noise. I'm thinking
of a scenario where one is silver printing a negative with 100 tones,
perhaps one is on grade 1 paper, the other grade 3, but both grades hold all
the tones. See, it forces an assumption of noise, which may or may not be
relevant.

Second, it also shows how incomplete a descriptor DyR is, if two so
radically different prints will yield the same value.

Third, in the hypothetical that both prints where produced by the same
system, where noise is the same between the two but the difference between
the two was artistic intent, what could possibly be the values that would
work in your formula to give you an identical DyR for these two prints?

I no unnastan! ;-)

Todd