Digital BW, The Print

Hi Everyone;

I have been making digital BW prints for over a year now and have hit
somewhat of a brick wall.

1/2 of my photographs are of landscapes and building. These images with
sharp lines and distinct textures print quite beautiful and problem free
using my Epson 1280 , MIS VM inks and Paul's curves.

The other 1/2 of my images are of portraits and nudes. These are much
more problematic in their printing. It seems that images that are soft
in focus in some areas or have very delicate wondering tonal transitions
are quite prone to posterization.  It is almost like when the piezo
heads have detail to print the do really well but when there is not much
detail to hold on to things go haywire.

I am following all the well established procedures of good imaging. I am
scanning well exposed medium format tmax-100 in 16 bit and an agfa
T2500. My scans are so good that they require very little curve changes
before printing. My histograms look good.

I am wondering at this point if it is one of two things that is causing
posterization on some of my images. (1) could it be that the set of
Paul's curves that I am using are just not fine tuned enough to work for
some images with my setup. Would switching to a professional RIP such as
ImagePrint or the Piezography Plugin and other inks allow me so print
these softer images without posterization? Have users of these RIPs
noticed a reduction in posterization problems?
 
(2) Could it be that the Piezo technology is just not capable of
printing these kinds of softer focus grayscale images with out some
posterization? Has anyone out there been able to print such images successfully??

Any input would be greatly appreciated!

-Jeff Magidson

SNIP
> 
> The other 1/2 of my images are of portraits and nudes. These are 
much > more problematic in their printing. It seems that images that 
are soft > in focus in some areas or have very delicate wondering 
tonal transitions > are quite prone to posterization.

> 
> Any input would be greatly appreciated!
> 
> -Jeff Magidson

SNIP

Jeff,

By no means have I mastered this...still experimenting in too many 
directions...however I have experienced exactly what your talking 
about and I've taken to printing those images simply WITHOUT any 
PRINTING curves.  I have been playing with printing from a CMYK file 
straight to the printer, it's just harder to influence the output 
color.  I "think" (since I'm not a very studious scientist) I can 
influence the color by using a "solid color" layer set to darken or 
burn.  

Once I realize an image won't take the printing curves I simply work 
it over in whatever file I like best for adjusting that image (any -
RGB, Greyscale or the CMYK) and print it with Epson's driver.

Sincerely,
Cleavis

I'm sorry I got on to this thread late because I have run into the 
described problem myself.

I run a digital imaging studio and print for a lot of different 
photographers so I see more varied
files than most.

I have tested several of the popular inks and workflows, currently using 
the MIS FS and the cone driver.

The "posterizing" and sometimes "edge breaks" are most evident in 
portraits and nudes but do
occur in other types of images.

My experience leads me to believe one of the basic problems with gray 
ink printing is that at the
precise tonallity where the different gray inks "cross over"undesireable 
things can happen.

The choice of papers does affect how this effect occurs, because of how 
each paper responds to different coverage.

I have had some sucess curing this problem by mismatching profiles and 
their papers.

Otherwise I alter the local contrast of the file where the tonal problem 
is manifested.

If one has not seen this ocuring, they are either extremely lucky or 
they are simply not viewing
their prints objectively enough.

Broken up histograms have almost no bearing on this "posterization" that 
I'm specifically referencing.

J.Z.