Sony A7R High ISO Noise Reduction
The Sony A7R offers only three High ISO& Noise Reduction settings: "Off", "Low" and "Normal" (default). The user manual doesn't say at what sensitivity High ISO Noise Reduction begins to be applied, so we've included crops from ISO 50 on up to find out.
See for yourself how the the default and lowest noise reduction settings compare to RAW files with no noise reduction or sharpening applied. Click on any of the crops below to see the corresponding full-sized image.
As you can see, the Sony A7R's High ISO Noise Reduction already has a noticeable effect at sensitivities as low as ISO 50, and the "Off" setting really isn't off (which is often the case), as the A7R still applies fairly strong chroma noise reduction with that setting at low to moderate ISOs.
With default noise reduction, you can see signs of Sony's new area-specific algorithm as it leaves high-frequency detail (and noise) around edges which can give them a somewhat rough look at higher ISOs. This helps produce crisper-looking prints at very high ISOs, but can look a little coarse and unrefined on screen at 100%.
As we've seen with some prior Sony models, the lower NR setting also blurs our difficult red-leaf swatch more than the default at ISOs 800 through 6400, while luminance noise levels are higher as expected. You can also see that the camera does a much better job than Adobe Camera Raw at suppressing moiré in the proportion scale and red-leaf swatch, though some is still visible in the red-leaf fabric in camera JPEGs.