Digital BW, The Print

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?

Hi Jan. The middle of an extended dynamic range will be different from
the middle of a lesser range. It goes with the territory :) ie: 5 is
the middle of a range of 11, 11 is middle of a range of 21 etc.

Regards
Duane




--- 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?
>

--- 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

i tend to look at this issue the same way.
see my post/question on this.

http://tech.groups.yahoo.com/group/DigitalBlackandWhiteThePrint/message/
90214

i do try to keep the midtones, as well as the lighter tones constant on 
any paper i use (though they are very few)

evan


> 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?
>