ISO Sensitivity / Noise levels (contd.)

In-camera High ISO noise reduction

The A200 offers a simple on/off option when it comes to High ISO noise reduction. Looking at our samples it is quite clear that 'OFF' doesn't mean that there is not any noise reduction applied. In fact the A200's JPEG engine always applies some noise reduction and the High ISO noise reduction is additional. If you prefer your images completely free of any noise-reduction, you'll have to shoot RAW.

This additional noise reduction attempts to address both chroma and luminance noise. It has no effect up to ISO 800 where the plots overlap each other almost exactly, before kicking-in at ISO 1600 and 3200. The results, visible in the stamp crops below, show that High ISO noise reduction has quite a significant impact. Visible noise is reduced dramatically but this is paid for with an equally dramatic loss of fine detail.

Indicated ISO sensitivity is on the horizontal axis of this graph, standard deviation of luminosity on the vertical axis.

Noise reduction crop comparisons (ISO 800 - 3200)

Off ISO 800	On ISO 800
Off ISO 1600	On ISO 1600
Off ISO 3200	On ISO 3200