Sony A7 High ISO NR
Sony A7 High ISO Noise Reduction
The Sony A7 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 A7'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 A7 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, haloed 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 lowest NR setting also blurs our difficult red-leaf swatch more than the default at ISOs 800 through 6400, even though luminance noise levels are higher as expected. Interestingly, moiré patterns in the red-leaf swatch are quite visible, despite the fact that the A7 is equipped with an optical low-pass filter. It must be quite a weak AA filter.