I'm collaborating with another person on scanning anime cels. But first we need to confirm that our scanners produce identical colors. So we picked one paint color that we both have and compared our scans.
I'm using an Epson Perfection v600 scanner, while my partner uses an Epson Expression 10000XL. We both calibrated our scanner using the Silverfast scanning software 8.8 with a 864 patches IT8 target. And our average deltaE are 0.6 and 1.0, which mean our scans should be color accurate.
However our testing scan on the same paint color looks noticeable different. Our hues are 243 to 233, that's enough difference to tell something is wrong. But I couldn't figure out where the problem came from.
For more testing, we both make a scan of our IT8 target under our calibrated profiles and saved under ProPhoto RGB color profile. When checked for proofing in photoshop, the gamut of my scan was within the AdobeRGB range but my partner's scan, many of the patches exceed AdobeRGB.
I uploaded my scanned target here. Target 1 is mine, target 2 is my partner's.