Digital BW, The Print

Thank you. What if A6<8? As in your EPSG?

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Steve Kale 
<stevekale@b...> wrote:
>
> Luminance (the Y in XYZ) = IF(A6>7.9996248, ((A6+16)/116)^3,
(A6*27)/24389)
> 
> 
> Where A6 is Lab L*.  Then
> 
> Density = -LOG10(Luminance)
> 
> 
> > From: Shilesh Jani <shileshjani@b...>
> > Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> > Date: Thu, 12 Jan 2006 16:01:28 -0000
> > To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> > Subject: [Digital BW] Convert LAB to Density Was: QuadTone RIP 
vs Epson inks
> > 
> > What is the formula for converting LAB values to density? My puny
> > mind is incapable of thinking in "L".
> > 
> > --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Steve Kale
> > <stevekale@b...> wrote:
> >> 
> >> I have heard that dye has likely been reintroduced with the K3
> > inks,
> >> possibly into the resin that encapsulates the pigment.  If I 
were
> > Epson I'd
> >> neither confirm nor deny this however and so we are unlikely to
> > ever really
> >> know for sure.  The MK ink, however, is the same from K2 to K3 
and
> > so this
> >> speculation would not apply to MK.
> >> 
> >> BTW I have been playing around with the Nanochromes.  Dmax on 
HPR
> > is Lab
> >> 10.5, 1.3, -1.6.   The same (black) ink on EPSG has Lab figures 
of
> > 5.3, 1.5,
> >> -3.5.  Epson Archival Matte paper has "normal" performance with
> > 14.8, 1.4,
> >> 0.4.  Of course we know nothing about longevity yet but if
> > it's "ok" in that
> >> respect then this could make a very nice universal black ink if
> > nothing
> >> else.  No bronzing at all that I can see so far on EPSG but I 
have
> > a lot
> >> more testing to do (I can't see any bronzing in the 918 target 
and
> > the
> >> finish to the inks is very nice).  So far I have just been 
making
> > ICC
> >> profiles for EAM, HPR and EPSG and also looking at the results 
of
> > printing
> >> the QTR Calibration Chart, all on my 2100.  The figures quoted
> > above are
> >> from the calibration page printed at 100% ink limit and reading
> > the 55%, 40%
> >> and 80% patches, ie in creating a QTR curve one would likely 
limit
> > K on HPR
> >> to at least 55%.  If I recall correctly, this is a lot lower 
than
> > what I
> >> used to use with the MIS UCs or Epson Ucs - I guess that would
> > save some
> >> ink.  LK is quite cool - 100% ink has Lab figures of 28.9, 
0.3, -
> > 5.7 (55%
> >> ink patch has 39.2, 0.2, -5.7).  It's late here and I'll type up
> > more of my
> >> preliminary work tomorrow and post profiles for those interested
> > in gamut.
> >> I must say though, a density of 1.92 on HPR looks very nice.
> >> 
> >> 
> >>> From: Paul Roark <paul.roark@v...>
> >>> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> >>> Date: Wed, 11 Jan 2006 15:05:42 -0800
> >>> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> >>> Subject: RE: [Digital BW] Re: QuadTone RIP vs Epson inks
> >>> 
> >>>> The Epson matte black has a dye component, ...
> >>> 
> >>> I don't think this is correct.  Do you have an Epson source for
> > this?
> >>> 
> >>> I've fade tested the UC MK, and it is very good -- right up
> > there with
> >>> Eboni.  The "hybrid" Epson blacks according to how they react 
in
> > my fade
> >>> tests are the Durabrite and "Archival" black inks.
> >>> 
> >>> Paul
> >>> www.PaulRoark.com
> >> 
> > 
> > 
> > 
> > 
> > 
> > 
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