Digital BW, The Print

Hello Peter,

> Just do the math.  At 2880x1440 DPI (the maximum for the 2200), the 
> printer can produce 4147200 dots/in^2.   If you are rendering an 
> image at 300 PPI each pixel in the original image gets only enough 
> real estate on the paper for 46 printer dots.   Since each dot of 
> black ink can only be black or ~black, that's not NEARLY enough to 
> represent a full tonal range!

Sorry, that's just theory.  I _know_, from real experience, that I can
print both high and low contrast images with the BO technique and get
beautifully rendered prints that match the digital images accurately.
It's a fact I can demonstrate.

I have in front of me as I write this, a print which has both high and
low contrast elements.  In the foreground is a tugboat in New York
harbor.  The tug is a high contrast element with whites, blacks, and
things in between.  In the distant foggy background is the New York
skyline.  It is low contrast.  Everything is just a few shades of
gray, with no blacks or whites.  Both are rendered accurately as they
appear on screen in PS7.

So your theory may be relevant in the classroom, but I live in the
real world.  That's the problem with theorists.  They just argue about
numbers while the people who do real work in the world find ways to
get things done.  Here's a story to illustrate the point:

HOW TO TELL A MATHEMATICIAN FROM AN ENGINEER

1) Place a sack with a million $ exactly in the middle of a long sofa.

2) Put the mathematician at one end of the sofa and the engineer at
the other.

3) Tell them that in a series of successive moves they each can move
one-half the distance toward the sack.  Whichever one gets there first
gets to keep the money.

4) The mathematician immediately jumps up and, with a gesture of
complete disgust, and walks away saying "That's ridiculous!  Anyone
with any intelligence knows that if you keep moving half the 
distance you'll never get there".

5) The engineer scoots over to the sack, picks it up, and walks away
saying "That's close enough for all practical purposes".

---------------

If I had to argue with you, I'd say that your theory, while probably
true on some level, is irrelevant for this subject, and therefore is
misapplied.  BO printing relies upon the eye to blend the dots.  What
creates different shades of gray is the distance between the dots and
the dither patterns.  

If you examine a BO print with a loupe you'll see that the Epson
driver does a masterful job at changing the spacing and the dither
patterns of the dots in order to render the most subtle difference in
tonality.  It really is quite amazing and beautiful, and I've grown to
love it's distinctive look.  

BTW, I agree that BO dots don't look like film grain and I think
that's a misleading way to describe BO printing.  However I think your
statement about Nicholas Hartmann in your other post in this thread is
poorly worded because you are basically calling him a liar.  The dots
may very well remind him of film grain.  Who are you to tell another
photographer how he should percieve things?
 

Regards,
Clayton


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