I've recently acquired a Minolta Scan Dual III (yesss, finally a film scanner). However, the scanner exhibits an odd "wavy" noise pattern, mainly noticable in dark areas. The following sample show it clearly. This was taken from a color slide, scanned using VueScan. And yes, I did allow the scanner to warm up, and I did use the "Calibrate" function in VueScan prior to scanning (several times, even). This is a 100% crop at full resolution with only basic sharpening applied: Depending on screen brightness, the noise is actually pretty noticeable. To show it more clearly, I've extracted the green channel (in this channel, the noise is most noticeable) and increased the contrast a lot using levels: Obviously, I would normally never do this, but it does serve to show that there appears to be some kind of issue. I've played around a bit with multi-sampling, which helps a bit, but the old adage of "garbage in, garbage out" applies here as well: if the individual scan is plagued by too much patterned noise, multi-sampling only does so much. Does anybody have a clue as to what is happening here? My gut feeling says something related with interference due to maybe the non-original power supply, or possibly some kind of voltage stabilisation internally not working properly to maybe old capacitors? Is this a known issue perhaps?