I've been using a G4050 for a few years. On my latest PC running the current Windows OS, I had to spring for the VueScan software because there didn't seem to be updated native HP software. And that's fine: VueScan is much better than the buggy, process-hog HP interface ever was.
I have no complaints with using the flatbed for scanning prints. But scanning 35mm negatives, oy.
While in flatbed scanning the focal point is situated directly atop the glass, transparency scanning apparently focuses a couple of microns higher. When I lay classic cardboard-mounted slides directly on the glass, they are in focus. But scanning negatives, either using the scanner's supplied 35mm mask, or my own custom-made cardboard mask, or just laying them right on the glass, almost never seems to hit the right focal point. And if there's any curl at all in the negatives, it's worse. And when I'm scanning the smaller half-frame negs from my Pen F (at max 2400 dpi), these focus and curl issues are all magnified.
Here's a scan I just did yesterday - a full-frame Tri-X negative scanned at 1200 dpi, shot with a Nikkormat and a non-AI 200mm/f4 Nikkor lens I was testing. I didn't crop the left edge of the negative so you can see how bowed upward it is.
While VueScan includes a setting for adjusting the focal plane position... the G4050 doesn't support that feature. D'oh!
I'm thinking I need to improve my homemade mask: Use a piece of cardboard the exact same thickness as half a slide mount for the under side; perhaps add a couple of struts across the top piece for the spaces between the negatives, or find some other way to press them flatter. (Not just laying a piece of glass on top, that would add lots of dust.) I suppose I could also put my negatives under some weight for a week or two before scanning them to reduce the curl... but who wants to wait when you have new negatives?
Alternatively, I know there are custom scanner masks available on Etsy, and perhaps elsewhere. Maybe there's already one out there somewhere that holds negatives at the exact focal point for transparencies on the G4050. Am I the only one dealing with this issue?
Does anybody have any suggestions?