Digital BW, The Print

Roy,

Good point.  I've been doing all of my work in QTR gray lab work  
space, but I wasn't aware of the 95-100 difference compared to gamma  
2.2.  Does this mean that if I make and icc profile using my QTR gray  
lab working space someone else using gamma 2.2 work space will  
experience a different result if they apply the same profile for  
printing or softproofing?

Carl

On Oct 20, 2005, at 4:30 PM, Roy Harrington wrote:

> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Paul Roark"
> <paul.roark@v...> wrote:
>
>>
>> I've printed several samples this morning to further explore the flat
>> 95-100% print separation issue.  Consistent with what Roy noted,  
>> I've found
>>
>
> ...
>
>
>>
>> What kind of 100% - 95% print separation (Lab L differences) are  
>> others
>> seeing with the Create ICC approach?  Is it just my system?
>>
>> Paul
>> www.PaulRoark.com
>>
>>
>
> There's been a lot of talk about the 95 to 100 range and what  
> separation can be
> and ought to be seen there.
>
> The one thing that I haven't seen emphasized is the issue of what  
> grayspace
> people are using.    100 is always dMax but where 95 falls is  
> dependent on
> what grayscale people are using.   Most often the default grayspace  
> that is used
> is GG 2.2.   This defines a very dark 95 step.  Put the eye dropper  
> on it and
> 100 to 95 is L=0 to L=1 a very much lower slope than most of the  
> range.  This is
> a definition issue not a matter of any calibration or device  
> quality.   This small
> step is often visible with a nicely calibrated monitor but on a  
> matte print the
> difference is very small.   Without CMM this can be fudged but as  
> the measurements
> get more precise I think this is a builtin side effect.
>
> This is one of the main reasons I create the Gray Lab space.  With  
> this space
> 100 to 95 shows as L=0 to L=5  -- 5 times the slope.  Note that the  
> only thing
> different is the grayspace used -- you make and use the ICC  
> profiles identically.
>
> Roy



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