... questo è quello che dice Dale Adams ex Anchor bay:
"A sharpness setting of 0 on the VP50 is the same as a sharpness setting of 1 on the VP30, so there is a difference. A setting of -1 on the VP50 is the same as a setting of 0 on the VP30. I believe this was changed due to some end-user complaints that the VP30 image wasn't 'sharp enough'. That wouldn't have been my choice, but I'm pretty sure that's what was done.
Note that sharpness control on these iScan models is done by altering the FIR filter behavior used by the filters in the scaling engine. Different sharpness settings use different sets of filter coefficients, which then change the high frequency behavior. The VP30's default setting and the VP50's sharpness setting of -1 use the same set of filter coefficients.