Digital BW, The Print

I have always found it rather counter intuitive that glossy papers give higher Dmax than do matte surfaces.  The explanation,  restating what I think Paul is describing, is that reflection from a perfectly smooth surface follows Snell's law: the angle of reflection equals the angle of incidence.  So, if light comes in from the side, it is reflected to the other side, and very little of it reaches a point right in front of the surface.  A matte surface is made up of lots of little surfaces facing lots of directions, and so some light always gets reflected forwards.  If we put a piece of glass in front of a matte surface, most of the light from the side is reflected to the other side, increasing the apparent Dmax.

I have always had a preference of the "un-ferrotyped glossy" look, and have been using Ilford Gold Fibre Silk as my "presentation" paper.  But, I like the *idea* of printing on a more natural surface, and I have lately been working with Premier Art Smooth BW.  What I think that I am starting to appreciate is that the loss of deep shadow density on the matte paper is balanced by a greater tonal range in the highlights. Some of this may have to do with the brightener in this paper, but the glossy papers I use have OBAs, too. I think that the relative effect on the highlights is the complement of what happens to the shadows: more light from the sides is reflected forward from the matte paper.

Any thoughts or comments?

David



--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Paul" <roark.paul@...> wrote:
>
> While we B&W types seem to obsess about our print dmax, it's instructive to put the numbers and readings in perspective.  In message 105399 dpgoldenberg33 noted that D=1.57 means that 2.7% of the light striking the paper is reflected.  D=1.7 means that 2% is reflected. To see the extent of the non-linear nature of these density numbers, see the graph at http://www.gravurexchange.com/gravurezine/0804-ezine/ploumidis.htm
> 
> I've also been noting that the spectro measurements are, in effect, using side lighting that is much more ideal than most of us have in the real world.  In fact, my 1% spot meter readings of glossy v. matte blacks on the wall indicate the matte blacks are often deeper.  This is contrary to what the spectro readings would indicate.  The spectros are not measuring total reflectance in all directions.  Yet in most real world situations the light is coming from lots of different directions, so total reflectance may be a more meaningful measure (but difficult to do).
> 
> To follow up on the significance of the reflective nature of the medium to its spectro readings, I just got a density reading of 1.75 from an ordinary glass mirror.  That's a great dmax from a mirror that reflects nearly all the light that hits it!
> 
> Paul
> www.PaulRoark.com
>