This camera - Coolpix P5100, like all the compacts that boast absurdly high pixel counts, is prone to image noise above ISO200. Below that point the images are clean enough, particularly if the end display medium is a 10 by 15 cm print. With Noise Reduction turned on in the menu there is some loss of fine detail at ISO400 and above. However, if your expectations are not too high, the output at a stratospheric ISO3200 is acceptable, with a bit of post-camera clean-up in noise removal software. The sad fact is that if this camera had a 7 megapixel sensor it would be a world-beater.
We really enjoyed using it, and as the only competition, the Canon G9, is also over-pixelled these are as good as it gets in compact cameras.