Digital BW, The Print

Christophe 

L* can easily be converted to density.  I have a simple spreadsheet with
these formulae:

If L* > 8 then XYZ_Y = ((L* + 16)/116)^3 else XYZ_Y = (L* x 27)/24389

Density = -log10(XYZ_Y)

Steve


> From: bwdigiprint <bwdigiprint@...>
> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Date: Tue, 14 Mar 2006 12:42:23 -0000
> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Subject: [Digital BW] Re: Paul's Recommended BW Workspace
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Peter De Smidt
> <pdesmidt@...> wrote:
>> 
>> So with all of the good info presented by Paul and others, I made my
>> first grayscale ICC today.  I printed Paul's 21 step stepwedge (with
>> 2.20 max density, as that's what I get with my R2400 and EPSM).  I
>> noticed that the profile embedded with the file is grayscale 2.2.  I
>> have been using Dot Gain 20%, as I've heard that it leads to more
> 'open' 
>> lower print values.  I didn't color manage the stepwedge. (That was the
>> right thing to do, right?) Should I change my working space to 2.2 when
>> I use the ICC?
>> 
>> BTW I used my MacBeth 914 reflection densitometer and coverted the
>> visual density to L* via a formula.
>> 
> Hello,
> I want to purchase an eye one spectrophotometer to make profiles for
> my printer but I wondered whether I can also read a density value fron
> that device (I need it to read target for alternative process like
> platinum printing). I find on www that there was not correlation
> between density and the L* chanel. You' d understand my interest for
> your formula! 
> Thanks for reply
> Christophe
> 
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