Recently I purchased a new CCD scanner for archival scanning of photographic prints. Looking over my scans, I noticed some vertical colored lines like the ones described here. I did the same test as the one described at that link and see the same results. So now I need to troubleshoot my new scanner or take it back, then rescan my photos.
Is that a fair test of a new scanner, or should we expect some faint colored lines as natural in a flatbed scanner? What are some other tests a person should perform on a new scanner before using it in production?
One other anomaly I noticed is that if I scan a photo at 1200 DPI right side up then upside down, sometimes I can’t get the two scans to line up perfectly, as if the motor inside the scanner doesn’t move in a perfectly constant velocity while scanning. Is there a name for this, a test for it, and is it also considered normal?