Digital BW, The Print

Hello Brian,

>Thanks for the response - it definitely helps!  
>In the ramp you posted for -25C,0M it looks like there is kind of 
>the "break" I was talking about in my ramps in the middle of the 
>100% step (looking the smooth part not the stepped part).  Is that 
>what you were talking about as not being possible to correct well?  

Yes.  First let me say that the images in the articles are very poor
and I hope to replace them with something better.  They were snapped
with a pocket digicam, rather than scanned, just a quickie job in the
wee hours.  Looking closely at the actual print, there is actually a
place around 90% where it gets lighter than at 85%, then drops off
quickly.  This bumpiness begins to show up after the slider value goes
beyond 15, either direction.  I haven't tested to see, but the degree
of this effect may vary on different papers.

>If you were going to try, because it's all "bunched" at that end, 
>what would you do?  

In an adjustment curve, any zone where the ramp has gone flat would
need a steep slope in the corresponding position to compensate.  In
the case of the place where it goes lighter for a bit, the adj curve
would require a dip to darken it.  In my experience this kind of
adjustment rarely works well.  The printed ramp is a response of the
paper to the ink load which is changed by the CM sliders.  It has
nothing to do with the image.  With a curve we're trying to adjust the
image to compensate for this.  Such radical curves usually cause badly
combed histograms and resulting posterization or related weirdities. 
At the very least the image must be in 16-bit if there's any chance it
will work.  My experience is that any such radical curves result in
some sort of ugliness in the print.  


>It takes a break of an association I'm used to making
>(screen=print) in order to think about it correctly.

Yes, it's one of the drawbacks of using the driver color controls for
anything - you can only see the result in the print.  


>I have not printed much on different papers yet but I can see how it 
>makes a difference - your breakdown in the paper chase article helps 
>as well.  I  really wanted to do most of the experimenting on the 
>cheap stuff (EEM) ;) 

Understood.  But after proofing when the paper and tone settings for
the final print are being determined, at least a few proofs on that
paper must be made to nail it all down.  Assuming this info is saved
in some way, this never has to be done again for subsequent prints.

Adapting to this system came easily to me because of my BO work.  I
have a nice collection of papers on hand (10 different ones besides
EEM, about 5 of which I use regularly).  Kayenta is the coldest, then
Condor BW and Peregrine Smooth (used to be called Merlin Smooth). 
Entrada is also coolish.  BTW, a friend has some Wm Turner for me (the
warmest), so I'll make a warm/cool set of ramps and add it to the
little range chart and put it in the article.  This will give a
relative idea of the full range of tones available to this approach.

Regards,
Clayton


Info on black and white digital printing at    
http://www.cjcom.net/digiprnarts.htm