I believe the point is that the scanner optical design itself is a limitation. I have a V850 and a Creo (top-end scanner) and the results are pretty dramatically different on 6x17, 4x5 and 8x10 particularly in the shadows and fine details. I'm archiving negatives so I want as much detail as possible. We all understand that the final print size and output type should be driving much of how we scan either way I assume.Just checked, and Vuescan can indeed do 6400 PPI if "Transparency" mode is selected. If "Transparency 8x10" is selected, then you only get 4800 PPI as your max resolution.