Digital BW, The Print

Without attempting to reply to all comments, let me add a little more to my
first post.

First, there was a specific allegation made in the Piezo review.  It claimed
that the Epson driver cannot utilize the information in an input file of
more than 360 DPI. Anything more that that would simply be discarded by the
driver.

This is demonstrably untrue.  The file I put in the forum's Files page shows
the utilization (barely, perhaps) of information beyond 360 dpi.  This print
was done using the usual MIS VM, RGB printing workflow.

Second, one can certainly debate what "sharpness" is.  Most of us have
probably followed the Modern/Popular Photography move to the Modulation
Transfer Function (MTF) as opposed to just the resolution figures.  The
optical companies' published MTF curves are great.  I wish I could measure
the MTF.  However, pure resolution -- the ability to separate black and
white lines -- is not irrelevant.  Popular Photography still uses it in many
tests, and it is something that most of us can relate to.  In my experience
it does correlate with the appearance of sharpness, even if the MTF might be
a more complete picture.  So, I think the posted file speaks for itself and
is relevant.

I also stick by the generally accepted 5 lp/mm visual resolution limit.
It's easy to test yourself.  I can't see more than 5 lp/mm.  However, as
Ctein and others have pointed out, even though most of us may not be able to
separate more than 5 lp/mm at normal viewing distance, we can detect edge
sharpness of closer to 30 lp/mm.  (The 30 lp/mm is Ctein's test result, as
best as I can remember.)

I have no idea how the inkjet output would measure up in edge sharpness, but
it would certainly not equal a good contact print.  However, most of us
don't to that.  My Epson 3000 16x20s are clearly sharper than my medium
format (Rollei/Zeiss/tripod/Tmax 100) traditionally-enlarged (Apo-Rodagon)
16x20s.

Having looked at a number of identical images that I've printed with both
the Piezo and Epson drivers, I must say in most cases I cannot see any
sharpness difference, even with a magnifier.  While the posted resolution
test would give the Epson driver a slight edge, I think if I could measure
MTF the Piezo driver would have an edge at certain frequencies due to dither
differences.  In that respect, I wonder if the newer drivers are actually
not as sharp as the old ones.  I suspect that hiding the micro-banding and
maximizing the MTF are diametrically opposed.  (My Piezo driver version is
the 511 update, 12/00.)

At any rate, I consider the drivers to be essentially equal in their ability
to deliver sharp results.  If the Epson dither lowers the technical MTF but
also hides the microbanding, I'd go with no microbanding -- which is the
original reason I started writing curves to print Piezo inks with the Epson
driver.  I suspect the Piezo drivers are going this direction also.

Paul
http://www.PaulRoark.com