Digital BW, The Print

Thanks Clayton!

The 'adjusting the image to compensate for the papers response to 
the ink load' explanation was very helpful.  I hadn't been thinking 
about it with regards to how the image would degrade with those 
attempts. 

When I originally was testing with the full set of neutral inks I 
was able to get the smoothest ramp by assigning the gray gamma 2.2 
profile to the image, adding a levels layer just to bump up the 
brightness to match the DG20 look (which I have been using as the 
default), and then printing with printer gamma 2.2.  I had several 
previous posts with you and Paul about it.  However, with this 
combination of inks I get the best ramp with DG20 and printer gamma 
1.8 (at C0,M0).  In one of my first messages to this group I talked 
about trying to reach a certain level of consistency... :P  I'm 
going to reprint the test series with DG20 and PG1.8 to see if I get 
better results.

BTW, I have not used QTR or any other RIP for any of this.  

Thanks,

Brian
http://www.brianchapmanphotography.com - Last updated June 12, 2006


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Clayton Jones" 
<cj@...> wrote:
>
> 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
>