D800 test revised

Revised number based on hacked D800, which has true dark level restored.

Gain = 2.4466 ADU/e-, at ISO 800.

Readout noise = 2.165 e- at room temperature at ISO 800
It becomes 2.13 e- at roughly 6 deg C.

Dark current is roughly 0.295 e-/sec at about 25.4 deg C, and 0.032 e-/sec at about 6 deg C.
The dark currents measured with mean dark counts and dark noise are consistent with each other.