I am a bit late in this conversation, but bear with me
I have used in the past slide duplicators (I still have them) and flatbed scanners. In a nutshell, you can make the copy, but the results are merely passable.
The trick is in the lighting.
The flatbed scanner might work (I've read) with a special film carrier that has special reflective backing. My experience without it was below mediocre.
I had above mediocre results scanning paper photos, especially if the colors remained stable and not migrated to magenta. I tried to batch the process, using the scanner feeder. After about 100 photos, the scanner head acquired a permanent (very hard to clean) paper ink(?) stain and all the scanned photos a line through them. I quit...
The film/slide duplicator tube, with the tube pointed at the sun, a white reflective surface (foamcore) etc. gave inconsistent, below mediocre results.
Back in 2012 I bought a Plustek OpticFilm 7400, on sale from B&H, a couple of hundred bucks. With hurricane Sandy and a move to Houston for professional reasons, the project was moved to the back burner (actually off the stove altogether). One of the reasons was that I run Linux and I knew it would take some effort to run (if at all) this kind of hardware.
Fast forward to Hurricane Harvey. We now live in Midtown, Houston. As part of the preparation, we moved all items from the ground floor to the first floor. In the process, I run into the filmscanner...
Being locked up for 5 days while Harvey was raining on us (thankfully we stayed high and dry) I started trying to make the scanner talk to Linux. Fail... No driver even barely compatible.
All my PCs have dual boot capability, so I run the Windows 7 the PC came with (oh the shame)
Here is what a scanned negative from September 1983 looks like straight out of the scanner. No noise reduction or other post handling, medium resolution (450 DPI for a 4x6 print, or 2656x1798 pixels) for a 2 Mb JPEG.
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I think the results are superb. This photo will be rescanned shortly, for a full frame resolution TIFF which will be suitably post-processed to have a large print for the wall!
The scanning process is manual (the film carriage does not autofeed) and slow, but the results are worth it.
I feel that for medium type resolutions (up to about 5200x3800 pixels) the resulting files are reasonable and the quality good enough to print 20x30 prints (which I seldom do). Nearly dSLR quality from my old Canon FTb!
I'll keep ypu posted.