CHROMiX

measure tool and gracol

In measure tool when measuring spot there is a reference and a
measured lab value

There is also a delta e value for differences between reference and
measured values

My question is how do I load the reference value so it displays the
Gracol standard lab say L 55 A* -37 b* -50 for cyan

then measure the sheet I have so I can see the delta e difference
between the gracol standard and what I have on the sheet

thanks

Mike

Mike,

I just tried a few different ways to measure say the ISO 12647 solids with Measure tool and it seems to me that the only way to use the Compare function is to actually measure a Reference then measure a Sample. There is a longer method that is awkward. You would some how measure your ISO solid LAB values with MT. This can be one at a time for example by measuring one color color in MT and then saving it and then opening it up in the Compare function and then measuring another one sample, save it and then open it in Compare. Another way is to use Color Picker and save out Solid Pantones. Oh yea, Pantone solids don’t quite match the ISO 12647 specification, even thought they want you to believe that. They are close, but no cigar.

If there are other ways to work with MT, I don’t get it yet.

Good luck.

Jim Rich

On 2/6/08 2:57 PM, “mikec” mikec@lawtonprinting.com wrote:

Post generated from email list

Thats kinda the way I saw it but you would have to have something with the gracol lab values to measure. Dont have anything

On another forum I got this reply

With something like a SpectroEye, you can hand enter a Lab reference
value and then compare directly on the instrument (SpectroEye has a
display that the Eye-One lacks). If it’s about G7 and ISO 12647-2
values, you can go to X-Rite’s website where they have a file that you
can upload to the SpectroEye with all the reference data already
there. You simply load the reference data you want for the specific
paper type and start measuring. This is great for taking on-press
measurements since you get a direct delta E comparison in real time
and you can make adjustments to the press accordingly (

Mike you could make a custom chart with the 4 solid colors on it.

Measure all 4 and save measurement data and use compare tool.

Thats what I did before getting my Xrite 528.

It works but not as easy and fast as the 528

John

Hello,

You could use Excel and Gretag Macbeth’s Keywizard software for this task. Keywizard (PC only) lets you connect to an Eye One (or a SpectroEye, Spectrolino, …) and it will transfer the Lab values of a measured patch to the frontmost application, in this case Excel. Somewhere in the worksheet you enter the reference values, and let Excel calculate the delta E between the reference and sample value. This is the flow I use to determine the relation wet density vs dry Cielab and delta E to find out optimum wet density. In Excel you can even automatically graph the relation between wet density and delta E.

Another way is a combination of Eye One Share, Color Picker (from the Gretag Profilemaker software) and Measuretool.
First with Color Picker enter the Lab values of the reference. Maybe enter the lab values of C, M, Y, K and paper white. Name the samples and save the file as CXF format (dongle required)
Next, in Measuretool, measure all the samples using a custom color chart. If you want to measure 10 values for example, enter columns ‘1’ and rows ‘10’, and start measuring the 10 samples with an Eye One. Save the file as CXF.
Place the file with 10 measurements in the ‘standards’ subdirectory of Eye One Share. On Mac OS X, you must click on the application, and choose Show Package Contents. Start Eye One share, and load the file with the reference values. Eye One Share will display a message that it will create the spectral values from Lab: this is ok. Resave the file once it has been converted too. Click on the cyan reference color, and in the bottom row with the libraries, choose the library with your measurement data. The library will be sorted from lowest dE to highest. To know the dE, drag your reference value to the left half of the big circle, and the left most patch from the library to the right half of the circle, or vice versa. Beneath the circle, dE is show between reference and sample.

Of course, you could measure your samples within Eye One Share directly too.

In the pressroom, I too use a SpectroEye with the ISO 12647-2 values loaded as a job. Together with it’s Bestmatch function, it even suggests to lower or raise density in order to obtain lowest delta E depending on the measured patch. Great tool.

Hope this helps you further a bit.

Regards,
Yann Bouckaert