Digital BW, The Print

davelongviews wrote:

> There has been a lot of discussion over extended periods on the group 
> regarding matte and glossy dmax. Is it true that light SCATTERED at 
> the paper surface is what gives a matte surface its look, and that 
> very same scattering is what reduces dmax? And with a glossy paper 
> less light is scattered, more is REFLECTED, dmax is greater, and you 
> have the glossyness to deal with. In other words isn't it true that 
> you can't have a matte surface with a truely large dmax? Aren't paper 
> surface/glossiness and dmax directly related in a way we wish they 
> weren't? Is it physically possible to separate the two? Any thoughts?
>
> Dave
>
>
Yes to all. This is explained pretty well in the book /Light Science & 
Magic/ by Hunter and Fuqua IIRC. In the early chapters they cover how 
objects reflect light. I can't find the book right off, so I'll have to 
broadly paraphrase.

Basically, matte object give a diffuse reflection, while glossy objects 
give off direct reflection. If you are looking at a matte print on axis, 
light coming from anywhere in front of the print is reflected difusely - 
that is, light coming in at a 10 degree angle is reflected back fairly 
equally across a 180 degree hemisphere. Some of this light reflects to 
your eyes.

If you try that with a glossy print, the light coming in at a 10 degree 
angle is reflected back off the print at 170 degrees. Almost none of it 
will reflect back into your eyes.

What it all comes down to is, glossy surfaces reflect less light into 
your eyes. It's the essence of being glossy. And it's the reason that 
glossy surfaces exhibit greater Dmax.
--
Bruce Watson