Digital BW, The Print

Steve,

>Sorry, is this meant to be a subjective empirical test? Ie which do I
>subjectively prefer?

Perhaps it’s an objective empirical test.  

I think there are a few bottom line, practical and useful goals.  Matching
the monitor would be one of those.  For this, some average lighting and
viewing conditions is going to have to be assumed.  Also, I don't know if
the calibration programs are very standardized.  But, if one did a pole of
actual users, then those factors would be included in the responses.

So, the question is, empirically, what midtone 50% print density best
matches the monitor.

Your numbers, below, suggest that by at least some theory my current target
of 0.61 might be "correct."  I also have a theory as to why it is "correct,"
but I also have a theory that suggests it is too light.  Frankly, I based my
0.61 standard on an empirical averaging of my and others' Piezo outputs some
years ago, where consistency with old files was the main concern.
Currently, however, I'd say most seem to think that the 0.61 50% target is
too light.  I assume these people are basically saying that the prints are
"lighter" appearing than their monitors.  As such they need to go through
some cumbersome process to match the two.  If that matching were better
built into the target, it might make life easier for many.

(Although I was once a math major, my experience has convinced me that
surveys and other empirical studies result in the best models.)

Paul
www.PaulRoark.com 





>I use a workspace of Gray Gamma 2.2.  Someone who knows the intricacies of
>this space better than I may correct me, but I would say that if:

>Luminance = C * value^gamma + black level

>(taken from Norman Koren's site)

>And we can usefully set C and black level to 1 and 0 respectively, then a
>normalised pixel value will have a luminance of 0.2176. If

>Density = - log10(luminance)

>Then it will have a density of -0.61.  Given it is a reflected density this
>then is 0.61.  That is, to match the workspace I would say it should print
>with a density of 0.61.

>I thought I had read somewhere that PS uses LAB as the intermediate colour
>space when converting from one space to another.  I also thought LAB had a
>gamma of 2.2.  Perhaps I am wrong on this.





________________________________
> From: Paul Roark <paul.roark@...>
> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Date: Fri, 3 Dec 2004 08:51:49 -0800
> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Subject: RE: [Digital BW] Tonal range and linearization
> 
> 
> Steve,
> 
>> Yes you are right because you in effect manually set the 50% grey slot
>> (presumably with some iteration).  My comment was made in relation to a
>> programme such as QTR where the midpoint is a function of
linearization...
> 
> Yes, it is an iterative process.  The driver is a bit of a black box, but
> once one gets used to it, it's quite predictable.
> 
> But, back to the simple question, would L=50 be a better midpoint?  If you
> print a 21-step test strip, like one at
> http://home1.gte.net/res09aij/Test-files.htm, would it match the monitor
> better if the midpoint were more like density 0.73 (a bit lighter than the
> current 60%) than the current 50% = 0.61?
> 
> Paul
> www.PaulRoark.com
> 
> 
> 
> 
> 
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Please visit the Group Homepage to check the Files, and other resources as
they are often being updated.

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If you wish to receive no emails or just a daily digest, or you wish to
unsubscribe, please edit your Membership preferences by visiting this same
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Please follow these basic guidelines:
- As threads develop, trim off excess portions of earlier messages to keep
them short.
- Good manners are required at all time. No personal attacks or flames.
Hostile, aggressive or argumentative users may be removed from the
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- Keep your posts and threads related to the group topic of digital B&W
printing. Users who persistently make off-topic posts may be removed from
the membership.
- By posting on this forum you agree to abide by the group rules and
guidelines, and to abide by the actions and decisions of the group Owner and
Moderators. See Group Topic, Rules and Guidelines in the Files section:
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BY PARTICIPATING IN AND/OR POSTING MESSAGES TO THE DIGITAL BW, THE PRINT
YAHOO! GROUP YOU EXPRESSLY UNDERSTAND AND AGREE THAT THE OWNER AND
MODERATORS OF DIGITAL BW, THE PRINT YAHOO GROUP SHALL NOT BE LIABLE TO YOU
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL OR EXEMPLARY
DAMAGES, INCLUDING BUT NOT LIMITED TO, DAMAGES FOR LOSS OF PROFITS,
GOODWILL, USE, DATA OR OTHER INTANGIBLE LOSSES (EVEN IF THE  OWNER AND
MODERATORS OF DIGITAL BW, THE PRINT YAHOO GROUP HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES), RESULTING FROM: (i) THE USE OR THE INABILITY
TO USE THE DIGITAL BW, THE PRINT YAHOO GROUP; (ii) UNAUTHORIZED ACCESS TO OR
ALTERATION OF YOUR TRANSMISSIONS OR DATA; (iii) STATEMENTS OR CONDUCT OF ANY
THIRD PARTY ON THE DIGITAL BW, THE PRINT YAHOO GROUP; OR (iv) ANY OTHER
MATTER RELATING TO THE DIGITAL BW, THE PRINT YAHOO GROUP.
 
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