Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Steve Kale
<stevekale@b...> wrote:

> The deeper blacks on photo paper with photo black ink have higher dMax
> because they reflect less light not more. 

Actually that is only true in the spectrometer example. They really do
reflect more concentrated light. Just not where the spectrometer is
looking. 

>The fact that photo papers
> produce a less diffuse reflection contributes to their sheen
characteristic
> but not their increased dMax.

The issues are pretty much one and the same from a practical
perspective. If the light direction enhances the "sheen" you have
visually less d'max and if it reduces the sheen you have more.

>It's the properties of the ink and other
> coatings in/on the paper which affect its ability to absorb light.

Yes, like glossy,satin, or matt coatings vs equal opacity/absorbant inks.


>The
> specular reflection characteristics of the surface are a different
issue?
> 

I think it is - the - main issue. If you could get d'max 3.0, via an
ink improvement, on matt, it's not going to alter the specular
relationships. Glossy could still do better.( under certain
circumstances ie: 45 degree lighting )

> I think what you are saying is that you are prepared to sacrifice
dMax in
> order to achieve less specular, more diffuse, reflection properties -
> particularly if you don't have "perfect" lighting. (I agree.)  But
this is
> not to say that glossy papers have an inherent advantage.  In fact their
> reflection properties is a big disadvantage - it is lucky they have
better
> dMax to make up for it.

I don't think they do.

>The question at hand is how much dMax loss are you
> prepared to take in order to have a more diffuse reflection? The answer
> probably hasn't changed much over the years (although I doubt it's been
> measured), only the relevant performance of each competing type of
> paper/ink.
> 
> 
> > From: Paul Roark <paul.roark@v...>
> 
> > 
> > The spectrophotometers we use for measuring dmax use nearly
perfect lighting
> > that avoids the problems of reflections.  This gives the glossy
papers a
> > huge advantage.  
> > 
> > In the real world, a matte print sitting on my desk top appears to
have a
> > better dmax than a gloss print because the glossy print dmax is
wiped out by
> > reflections.  That is, the nature of the lighting is what makes
all the
> > difference.  If the display conditions are perfect, the glossy
prints are
> > terrific.  If the lighting is bad, like a window behind the
viewer, matte
> > wins.  
> > 
> >