ISO Sensitivity / Noise levels (contd.)

In-camera High ISO noise reduction

The K200D offers four levels of High ISO noise reduction: Off, weakest, weak and strong. Looking at our samples it is quite clear that 'OFF' doesn't mean that there is not any noise reduction applied. The K200D's JPEG engine always applies some noise reduction and the level of High ISO noise reduction you choose comes on top of this. If you want images that are completely free of any noise-reduction, you'll have to shoot RAW.

The additional noise reduction attempts to address both chroma and luminance noise. It has no effect up to ISO 400 where the plots overlap each other almost exactly, before kicking-in at ISO 800 and 1600. The results, visible in the stamp crops below, show that High ISO noise reduction in its 'weakest' setting has indeed a very subtle effect, only adding a small amount of chroma noise reduction to the default parameters. The 'weak' and 'strong' settings are very similar and much more aggressive which results in visibly softer output and a 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 400	Weakest ISO 400	Weak ISO 400	Strong ISO 400
Off ISO 800	Weakest ISO 800	Weak ISO 800	Strong ISO 800
Off ISO 1600	Weakest ISO 1600	Weak ISO 1600	Strong ISO 1600