Digital BW, The Print

> The colour black is the sensation we perceive due to the absence of (in this
> case) reflected light. 

Good point, although I don't agree entirely. Black is the absence of light, period. If light is 
either scattered back to the viewer from the object, or reflected, either way it makes gray 
shall we say.

Most of today's spectrophotometers project D50
> lighting at 0 degrees and measure the light reflected back at 45 degrees.
> The deeper blacks on photo paper with photo black ink have higher dMax
> because they reflect less light not more. 

Again, I don't know if I agree. Reflected light reflects back at the same angle it goes in 
(towards the paper surface in this case). In the case of the 45 degree angle with the 
spectrophotometer, the photo papers reflect more (back at 0 degrees) but don't scatter as 
much (back to 45 degrees the way matte papers do). Thus photo versus matte papers 
show higher dmax as measured at 45 degrees. So to my way of thinking dmax and 
glossyness are inextricably tied. Witness Pauls observations on Arches hot press. It is not 
just "lucky" that glossy papers have a higher dmax. It's because they are glossy that they 
have a high dmax. Put another way: Matte surfaces scatter a lot of light relative to glossy. 
Light coming into a surface is scattered at a wide range of angles, making everything in 
effect grey.


>The fact that photo papers
> produce a less diffuse reflection contributes to their sheen characteristic
> but not their increased dMax.  It's the properties of the ink and other
> coatings in/on the paper which affect its ability to absorb light.  The
> specular reflection characteristics of the surface are a different issue?
> 
> 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.  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.  
> > 
> >