ISO Sensitivity / Noise levels (contd.)

In-camera High ISO noise reduction

The D90 has four Noise Reduction settings, High, Normal, Low and Off - the three active settings have an effect at all ISO settings. These settings do not appear to make any distinction between chroma (color) and luminance noise, so the choice they offer is how much detail you want smoothed away along with the noise, as there's no option to remove only chroma noise and allow the luminance 'grain' to remain. The Noise Reduction Off setting or shooting RAW does allow the use of third-party software to achieve this, however.

Indicated ISO sensitivity is on the horizontal axis of this graph, standard deviation of luminosity on the vertical axis (note that the standard deviation scale here has been extended 3x compared to the graphs on the previous page).

Noise reduction crop comparisons (ISO 800 - 6400)

ISO 800
NR Off		 ISO 800
NR Low		 ISO 800
NR Normal		 ISO 800
NR High
ISO 1600
NR Off		 ISO 1600
NR Low		 ISO 1600
NR Normal		 ISO 1600
NR High
ISO 3200
NR Off		 ISO 3200
NR Low		 ISO 3200
NR Normal		 ISO 3200
NR High
ISO 6400
NR Off		 ISO 6400
NR Low		 ISO 6400
NR Normal		 ISO 6400
NR High