Digital BW, The Print

Shilesh

QTR uses a flag called UC_Neutraliser to copy the LK curve to the LC and LM
position when using the UC inks.  What this means is that the LC and LM inks
are used to neutralise the LK only.  You can look at the hue of the combined
ink by printing the UC calibration chart in calibration mode.  I know these
things aren't visible to PC users yet but they are there for the Mac guys to
see and use.  For a cool curve we use equal amounts of LC and LM to cool the
LK.  In essence it is this adjusted LK that gets partitioned with K to make
a cool curve.  With the warm UC curves the LK is not cooled.   With sepia, a
little yellow is added to the LK.

Steve


> From: Shilesh Jani <shilesh.jani@...>
> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Date: Sat, 29 Jan 2005 01:43:07 -0000
> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Subject: [Digital BW] Roy Correct Me If I Am Wrong:  Piezography? Or, the
> state of the state. (Roy
> 
> 
> 
> Mitch,
> 
> You raise a very important distinction between the canned QTR set-up
> and IP.  I believe with QTR on UC inks the preponderence of inks
> layed down are black, and light black.  Light magenta and light cyan
> are used only to control warm/cool/selenium (although they provide
> density too).  Yellow is used only on sepia curves.  No use is made
> of magenta and cyan inks, specifically to reduce/eliminate
> metamerism.  The Photoblack ink of UC is supposed to be extremely
> warm (more so than matte black), and is difficult to neutralize with
> just the light magenta and light cyan.  IP may work differently, but
> could introduce the dreaded metamerism, and infact I remember seeing
> a demo of IP where b/w prints were made with specific viewing
> conditions in mind.  Not an issue for many people - but I find hue
> shifts rather annoying.
> 
> Shilesh