Confused about IT-8 calibration

[halaja]

I am using Silverfast 5.5.2 with my Epson Perfection 2400 photo.
I calibrated the scanner using silverfast's IT-8 module with the following settings:
-scanner->internal:none
-internal->monitor:none
-internal->output:RGB
-gamma for prescan:tried the range between 1.8 and 2.2
using a kodak Q60 reflective target with the corresponding reference file.
By opening the profile that is created by Silverfast in a profile viewer, the profile seems to have a bit smaller gamut, than the sRGB profile has.
Calibrating the same scanner with GretagMacbeth's ProfileMaker yields to different results, a brighter calibrated scan, and a profile with much larger gamut, than sRGB.

After calibration, with Silverfast's CMS on, using the profile generated by Silverfast, the scan looks similar to the target, but has a very slight red cast (sampled in Photoshop with 3by3 average sampling), and the GS11 patch has a value around 110.

What do I wrong? Are my Silverfast CMS settings right for calibration?
Shouldn't my scanner have a larger gamut, than sRGB?
How can I determine if the calibration is correct?

Thank you in advance
Lajos Hajdu

[LSI_Muenier]

Just a guess: could it be that your scanner was not "warm" when you performed the IT8 calibration? Then later scans could result in color casts.

[LSI_Noack]

Dear Lajos

any settings made in SilverFast don't interfere with the calibration procedure, as the software uses standard settings for the calibration.

This is too make sure that the profile generated is useful for all scanning purposes and no "double-adjustments" may occur.
Furthermore, this feature was provided for the users, so that they don't need to care about setting back all adjustments manually.

For a real scan, however, you would need to set "scanner > internal" different from "none" or your profile generated will not be used.

Because I don't have Gretag MacBeth's software at my office desk, I need to ask for your patience, until a colleague will have checked this out for me.
Thank you for your kind understanding

[halaja]

Thank you for your response, and the explanation, how SF's CMS works.
I made a comparison of the results of different calibration procedures (Silverfast 5.52 and Profile Maker 4.5, calibrated with 2.2 gamma setting in both case).
I scanned an IT-8 target using Silverfast with CMS turned off and gamma set to 2.2, "for HDR output" checked. Saved it as .tif.
I opened it in Photoshop and assigned the different profiles to it, using Adobe RGB as working space.
I created a layered image of the above mentioned images and compared it to the computer simulated version of the IT-8 target I have (based on the target reference file).
On the monitor, the results from Silverfast 5.52 are visually almost identical to the simulated image (Profile Maker's results show more difference, mainly in brightness and contrast), but I don't know, how they look printed, especially, when the printer has a larger gamut, than sRGB.