Digital BW, The Print

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?


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