I found some lines in dualiso pdf:
5. Mixing the two exposures: "So, why not just use the
ISO 1600 data everywhere, besides the top 4 stops? Because resolution matters too, and so does
aliasing and moire."
5.1 Recovering the full resolution in midtones:
"As you can see from Figure 7, the result with the smooth transition is a little on the soft side (but
without any banding). The midtones created without any interpolated pixels (Figure 7, bottom)
have the same resolution as a normal picture (without dual ISO), but has some slight banding
artifacts."
"...in this case you’ll have to live
with a softer image, obtained only with curve (9), which does not have any banding."
That makes me think that banding in shadows and highlights appears while recovering full resolution midtones. Is it correct?
Is it possible to trade half resolution to have zero banding?
I hope I managed to make it a bit more clear.