Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "jan_lindahl" <jan_lindahl@...> 
wrote:
>
> For some time now I've been using QTR for my black an white prints. 
> I've been reading Tom Moores excellent User Guide with great interest.
> One thing puzzles me though. In figure 11 – Table of Ideal Desities, 
> Tom suggest, that with increasing dMax the print as a hole shall print 
> darker and darker, So a 50% grey will have a density of 0.568 with a 
> dMax 1.60 paper, and much darker, 0.711 with a dMax 2.4 paper. Wouldn't 
> it be more logic to balance the curve with a constant midtonevalue?? 
> And what should that value be?
>

"Table of Ideal Densities" is a bit of a misnomer.  What the table shows are values
for a "Linearized" curve.  For QTR linearized means linear in Lab values so this
table shows what the linear Lab values look like if converted to density units.

Your idea of a "constant midtone" is quite reasonable and if you get into using
color management and icc profiles this notion comes into play.  But things get a
fair amount more involved because 50% gray means something different in each
profile space i.e. gray gamma 2.2 versus gamma 1.8 versus dotgain 25 etc.
So the QTR linearized values are just a standard for color management to be
built upon.

Roy