Beyond the Digital Zone System—ISO 400 and 3200
While I was at it, I made exposures at ISO 400 and 3200 as well.

ISO 80, for comparison.

A little shadow noise beginning to appear in N+4. Slight loss of highlight detail.

Massive shadow noise. More loss of highlight detail.
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The toe of the ISO 3200, N curve is slightly elevated due to noise.
The N+4 curve is greatly elevated by massive noise.  Both of these are zone -VI exposures.

Raising the Shadows slider reduces visible noise at the expense of compressing the tonal range.