Digital BW, The Print

> Would this be a case where converting back to 16-bit just prior to printing
> would be in order?


Martin,

yes, exactly - or to 720dpi  for that matter.


> 
> I know you beta tested the IJC/OPM software and are a long time user of the
> Piezo/R9 plug-in. Can you give us your comparison of print quality and
> workflow quality of the two?

well.... yes, I suppose I should. I would need to print the same file both ways 
and upload detailed scans of the prints. I can do that with the 1280/PT 
seleniums. ..   OK, "coming soon"....

Meanwhile, by way of a (lengthy) prologue:

The main difference between IJC/OPM and systems that use canned profiles 
is not just the accurate match of the profile to the user's system but the fact that 
you gain "analogue" control of the tonal distribution of your print.  This applies 
to any Raster Image Processor that gives you single channel control of the 
printer, not just OPM.

When you tweak RGB curves, or  tweak a grayscale file based on a monitor 
preview (or printed output) you are altering the digital data in the picture. 
That's normally where people are careful with scans and histograms, do some 
moves in 16bit etc. trying protect the tonal integrity of that data.  I call that 
"digital" corrections or adjustments that take place  in the digital domain.

When you tweak how much ink - and in what combination of colors or grays - 
is layed down for each digital value in the image, you are performing an 
"analogue" correction. Sure, it's handled digitally, but it is not dependent on 
the digital data in the image file. It only becomes related to it  when the 
software "looks up" the digital value in the image and matches it up with your 
choice of amount of ink(s). In this scenario, you can lighten/darken etc without 
affecting the precious bits and bytes in the original file. I call it  "analogue",  
(like audio D/A converters) because it occurs at the point where pixels are 
converted into the appearance of a continuous tone print. 

This "analogue" option is not available when the controls are locked away in a 
black box like the Epson driver or the R9 plug in or ImagePrint etc. Now, there 
may be good reasons for locking them away - there is serious complexity in 
reproducing CcMmYK color prints from RGB files and companies like 
Colorbyte have brought a lot of science to help us out. 
In the case of bw, it takes  a fairly knowledgable user to make a profile and 
understand how you partiton the grayscale into the 2-7 inks you may be using 
to print. So, this may not be for everyone, and there may be plenty of happy 
users of canned profiles (as Tyler points out) - fair enough.  Of course, as 
profiles become available for OPM, not only are they canned and easy-to-use, 
the whole thing is free, which is another matter to consider!

By the same token, we need to be aware of what we are doing to our digital 
data when (and if) we have to twist it because of  inaccuracies in our printing 
systems. When you make a bw print with a "locked" system, then adjust your 
image to improve that print, some of the adjustments are part of  the artistic 
interperetation, of course, but a fair amount may be aimed at  counteracting 
the effects of an out-of-whack system. You will never be able to separate the 
two without  access to the print controls of the driver independently of the 
image file.

So, these are the theoretical reasons for seeking out systems that allow 
"analogue"  tweaks. Now, it doesn't mean that everything else is garbage, nor 
that the ability to have these controls automatically makes a software superior.  
I am happy to see the introduction into the arena of monochrome printing  of 
the Ergosoft product (at inkjetmall), because it appears to address the issues I 
am talking about. I have not had any experience with it (because I am 
Windoze-challenged) but have pretty high hopes for its performance based on 
reviews and on line discussions.  It may be several times the cost of IJC, but I 
believe it also supports more large format printers without the limitations of 
IJC. We've seen leapfrogging before - let's see what's in store next....
 
Antonis