1) This picture is taken with ISO1600 - Single Drive Mode (Noise Reduction ON). Well preserved details and insignificant Noise/Grains
2) Significant Noise/Grains appears on this pic below; ISO1600 - Multiple/Continuos Burst Mode( Noise Reduction ON)
3）Significantly LESS NOISE/Grains was noticed in this picture below; taken with ISO1600 - Single Drive Mode
Many may not realize that even though that the Noise Reduction function had turned to ON but it doesn't apply when we shoot in Multiple/Continuos Burst Mode. This is due to insufficient time for the Bionz processor to process the image. Infact, this doesn't only apply to Sony but other DSLR as well, unless those high end professional DSLR. High ISO Noise Reduction will only be functioning smooth and nice when Single Mode is selected.