Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Steve Kale <stevekale@b...> 
wrote:
> And mid grey has 18% reflectance/L*=50 or some other level?

Middle gray is half-way between the dMin and the dMax of a gray ramp of course.
But one can decide where to put that in terms of visual density by using a Gamma 
correction to the linearization, or making a linearization based on a specific Gamma.

In a linearization based on Gamma 1.0 its too light for most humans to see it as "middle 
gray", and on 2.2 its too dark, and on 1.8 I think its just right.

So for our supportive curves to QuadTone RIP we will put "middle gray" at a point where 
we think the human eye interprets it as the "visually logical" mid-point between dMin and 
dMax. This is also our intention with iQuads and PiezographyBW ICC.

So middle value gray at 127/128 can be represented differently and we try to represent it 
based on the Gamma of 1.8 as applied against dMin and dMax.

best,

Jon