Blue CI calibration and dendro measurements

Last update: 27 January 2016

This describes blue channel calibration mechanisms as done with CooRecorder version 8.1

In this section we will make blue CI measurements on a Norway spruce sample and compare the Latewood CI results from

an Epson Perfection V750 with Silverfast and CooRecorder calibration - to be used as the main reference
an Epson Perfection V750 with only Silverfast
the same Epson Perfection V750 but with EpsonScan and its default ICM
as above, the same Epson Perfection V750 with EpsonScan and its default ICM but also with CooRecorder calibration
an Epson 2580 with EpsonScan and default ICM settings

From the previous section "Blue CI calibration with EpsonScan, VueScan and CooRecorder" we know that in "case 3" above the image is a bit too dark, so in "case 4" we will adjust for that by using CooRecorder calibration. Finally we will show that the Epson 2580 with standard settings produces about the same result as in "case 1" and "case 4"

The two CI collectors are set up as shown above.

CI data for latewood, earlywood and "DeltaBlue" is generated for the Epson V750 and an image created with Silverfast calibration with "Perceptual" for "Rendering Intent"

Then the corresponding CI data is generated for "case 2, 3, 4 and 5".

Epson 750 with Silverfast compared to Epson 750 with Silverfast and CooRecorder calibration.
CooRecorder makes some small adjustments to the Silverfast calibration.

Epson 750 with EpsonScan/ICM compared to Epson 750 with Silverfast and CooRecorder calibration.
Big problems!

Epson 750 with EpsonScan/ICM and CooRecorder calibration compared to Epson 750 with Silverfast and CooRecorder calibration.
Is this an alternative to using Silverfast for the 750 scanner?

Epson 2580 with EpsonScan and default ICM settings compared to Epson 750 with Silverfast and CooRecorder calibration.
A scanner that produces calibrated blue values without any problems!?

Please notice that "Ind.ring-w scaling" (Individual ring width scaling) should be checked OFF to make the curves plotted with the same scale!
At Settings/Plotting window settings you can also have "Individual ring width scaling by default" set as you prefer.