For a few years I have been scanning film, originally my old negatives and more recently my new Hasselblad film images.
I started with an Epson 4870 flat bed and soon learned that it wasn’t giving me the quality of scan that I knew my negatives deserved. There was a trouble with a flat bed like that, it didn’t have any accurate focusing instead relying on a pre-set focus. That required the negative to be at the exact focus point the manufacturer had pre-set. Alas the Epson holders weren’t engineered accurately enough and my images were not ‘grain’ sharp. Just as in the old dark-room printing days I judged the sharpness by the film grain.