Digital BW, The Print

So density is always a negative number?  I thought we talked about density
figures as positive numbers eg a dMax of 1.64.  In Roy¹s calibration doc he
has numbers like 127, 121, 131....  (I am taking the middle number from the
Sample spot measurement in the XYZ space using Measure Tool¹s Spot
Measurement function ie a dark black is producing a y value of around 2.0)

Is there a useful book for this kind of stuff?

(Re the Eye-One, I was about to do exactly the same thing.)

Presumably the level of 60 for LK was set using the process described in the
Calibration document....


Ahhh I am getting lost here....


From: Carl Schofield <scho@...>
Reply-To: DigitalBlackandWhiteThePrint@yahoogroups.com
Date: Mon, 22 Dec 2003 14:48:56 -0500
To: DigitalBlackandWhiteThePrint@yahoogroups.com
Subject: Re: [Digital BW] Calculating density values with Eye-One

Steve,

You can calculate density from either the "L" values from the LAB data
or directly from the "Y" number in the XYZ data:

If L > 8
Y = ((L + 16)/116)^3
Else
Y = (L * 27)/24389

Density = -log10(Y)

I have no problems with the eye-one rubbing on the patches when using
the strip reader.  I have attached an 8.5x11 inch sheet of pictorico
high gloss white film to the underside of the back edge of the strip
ruler so the feet on the eye-one slide more smoothly when making strip
measurements.

Carl
On Monday, December 22, 2003, at 02:28  PM, Steve Kale wrote:

> From my other posts you can see that I am trying to improve my
> knowledge of QTR.
> However, I also have a very basic question potentially applicable to a
> broader
> audience.  How can I use an Eye-One Photospectrometer to calculate
> density values.  I
> can see how to take a spot measurement of a patch and get an answer in
> a variety of
> colour spaces but how are these then converted to density values?
>
> Thanks
>
> Steve
>
> PS:  do others have problems with the Eye-One rubbing along the
> surface of patch
> strips when using the strip ruler?


[Non-text portions of this message have been removed]



Please visit the Group Homepage to check the Files, and other resources as
they are often being updated.

http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint

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
page.

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
membership without notice.
- 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:
http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/files/

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.




Yahoo! Groups Links
* To visit your group on the web, go to:
* http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/
*  
* To unsubscribe from this group, send an email to:
* DigitalBlackandWhiteThePrint-unsubscribe@yahoogroups.com
<mailto:DigitalBlackandWhiteThePrint-unsubscribe@yahoogroups.com?subject=Uns
ubscribe> 
*  
* Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service
<http://docs.yahoo.com/info/terms/> .




[Non-text portions of this message have been removed]